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{{Short description|Burning of the skin by the sun's radiation}}
:''For information on the the Florida regional [[Burning Man]] event, see [[SunBurn]]. For information about the anti-ship missiles, see [[SS-N-22 Sunburn]].''
{{Other uses}}
A '''sunburn''' is a [[radiation burn]] to the [[skin]] produced by overexposure to [[ultraviolet]] (UV) light, commonly from the [[sun]]'s rays. A similar burn can be produced by overexposure to other sources of [[UV]], such as tanning lamps and [[welding]] arcs. Exposure of the skin to lesser amounts of UV will often produce a [[sun tanning|suntan]].
{{Use American English|date=September 2022}}
{{Use dmy dates|date=September 2022}}
{{Infobox medical condition (new)
| name = Sunburn
| synonyms =
| image = Sunburn Treatment Practices.jpg
| alt =
| caption = A sunburnt neck
| pronounce =
| field = [[Dermatology]]
| symptoms =
| complications = [[Skin cancer]]
| onset =
| duration =
| types =
| causes =
| risks = Working outdoors, skin unprotected by clothes or [[sunscreen]], [[Fitzpatrick scale|skin type]], age
| diagnosis =
| differential =
| prevention = Use of [[sunscreen]], [[sun protective clothing]]
| treatment = Avoiding further exposure to the sun. Cool, frequent baths or showers for pain relief. Anti-inflammatory medications such as ibuprofen or aspirin can also help with pain. Drinking water to stay hydrated.
| medication =
| prognosis =
| frequency =
| deaths =
}}<!-- Definition and symptoms -->
'''Sunburn''' is a form of [[radiation burn]] that affects [[living tissue]], such as [[skin]], that results from an overexposure to [[ultraviolet]] (UV) radiation, usually from the [[Sun]]. Common symptoms in humans and other animals include [[erythema|red or reddish skin]] that is hot to the touch or [[pain]]ful, general [[fatigue]], and mild [[dizziness]]. Other symptoms include [[blister]]ing, [[peeling skin]], swelling, itching, and nausea. Excessive UV radiation is the leading cause of (primarily) [[Malignancy|non-malignant]] [[Neoplasm|skin tumors]],<ref name="Do sunscreens prevent skin cancer">[[World Health Organization]], International Agency for Research on Cancer [http://www.iarc.fr/ENG/Press_Releases/archives/pr132a.html "Do sunscreens prevent skin cancer"] {{Webarchive|url=https://web.archive.org/web/20061126075700/http://www.iarc.fr/ENG/Press_Releases/archives/pr132a.html |date=26 November 2006 }} Press release No. 132, 5 June 2000</ref><ref name="Solar and ultraviolet radiation">[[World Health Organization]], International Agency for Research on Cancer [http://monographs.iarc.fr/ENG/Monographs/vol55/volume55.pdf "Solar and ultraviolet radiation"] {{Webarchive|url=https://web.archive.org/web/20130729122453/http://monographs.iarc.fr/ENG/Monographs/vol55/volume55.pdf |date=29 July 2013 }} IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 55, November 1997</ref> which in extreme cases can be life-threatening. <!--
Mechanism --> Sunburn is an [[Inflammation|inflammatory]] response in the tissue triggered by [[direct DNA damage]] by UV radiation. When the [[Cell (biology)|cells]]' [[DNA]] is overly damaged by UV radiation, [[Apoptosis|type I cell-death]] is triggered and the tissue is replaced.<ref name=":1">{{EMedicine|emerg|798|Sunburn}}</ref>
<!--
Prevention -->


Sun protective measures like [[sunscreen]] and [[sun protective clothing]] are widely accepted to prevent sunburn and some types of [[skin cancer]].<ref>{{Cite journal |last=Maslin |first=Douglas L. |date=November 2014 |title=Do suncreens protect us? |journal=International Journal of Dermatology |language=en |volume=53 |issue=11 |pages=1319–1323 |doi=10.1111/ijd.12606 |pmid=25208462 |s2cid=205188894 |doi-access=free }}</ref> Special populations, including children, are especially susceptible to sunburn and protective measures should be used to prevent damage.<ref>{{Cite journal |last1=Dusza |first1=Stephen W. |last2=Halpern |first2=Allan C. |last3=Satagopan |first3=Jaya M. |last4=Oliveria |first4=Susan A. |last5=Weinstock |first5=Martin A. |last6=Scope |first6=Alon |last7=Berwick |first7=Marianne |last8=Geller |first8=Alan C. |date=February 2012 |title=Prospective Study of Sunburn and Sun Behavior Patterns During Adolescence |journal=Pediatrics |volume=129 |issue=2 |pages=309–317 |doi=10.1542/peds.2011-0104 |issn=0031-4005 |pmc=3269110 |pmid=22271688}}</ref>
[[Image:Sunburn.jpg|thumb|Sunburn. Image courtesy of John L. Bezzant, M.D. and the [[Spencer S. Eccles Health Sciences Library]].]]
{{TOC limit}}


==Development and consequences==
==Signs and symptoms==
[[File:Sunburn blisters.jpg|thumb|303x303px|[[Blister]]s on a sunburned shoulder]]
Typically, there is initial redness, followed by varying degrees of pain, the severity of which correlates with the duration and intensity of sun exposure.{{citation needed|date=February 2023}}


Other symptoms can include [[blister]]ing, swelling ([[edema]]), itching ([[pruritus]]), [[peeling skin]], [[rash]], [[nausea]], [[fever]], [[chills]], and fainting ([[Syncope (medicine)|syncope]]). Also, heat is produced from capillaries close to the skin surface, therefore the affected area feels warm to touch. Sunburns may be classified as superficial or partial-thickness [[burn (injury)|burns]]. Blistering is a sign of second-degree sunburn.<ref>{{Cite web|url=https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn|title=How to treat sunburn {{!}} American Academy of Dermatology|website=www.aad.org|access-date=29 March 2018|archive-date=20 March 2018|archive-url=https://web.archive.org/web/20180320170809/https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn|url-status=live}}</ref>
Sunburn usually develops as a result of over-exposure to sun or less commonly, occupational exposure. Typically, there is substantial pain associated with sunburn.


===Variations===
Sunburn occurs when exposure to UV light exceeds the protective capacity of an individual's [[melanin]]. Melanin content varies greatly, but in general darker-skinned people have more melanin than those with lighter skin. This leads to a reduced incidence of sunburn amongst dark-skinned individuals.
Minor sunburns typically cause nothing more than slight redness and tenderness to the affected areas. In more serious cases, blistering can occur. Extreme sunburns can be painful to the point of debilitation and may require hospital care.<ref>{{Cite journal |last1=Guy |first1=Gery P. |last2=Berkowitz |first2=Zahava |last3=Watson |first3=Meg |date=2017-01-01 |title=Estimated Cost of Sunburn-Associated Visits to US Hospital Emergency Departments |url=http://dx.doi.org/10.1001/jamadermatol.2016.4231 |journal=JAMA Dermatology |volume=153 |issue=1 |pages=90–92 |doi=10.1001/jamadermatol.2016.4231 |pmid=27902809 |s2cid=8254557 |issn=2168-6068|pmc=6057474 }}</ref>


===Duration===
Ultraviolet radiation is divided into UVA (380–315 nm), UVB (315–280 nm) and UVC (280-180 nm) subtypes. [[Ozone]] in the [[Earth's atmosphere]] filters out some UV radiation. UVC is almost entirely eliminated by the atmosphere, but enough UVA and UVB remain that sunburn can occur in less than 15 minutes. [http://203.202.189.11/browse.asp?ContainerID=1560] UVB was thought to be the causative agent in skin cancer, but there is a growing body of evidence to support the theory that both UVA and UVB cause skin cancer.
Sunburn can occur in less than 15 minutes in response to sun exposure and in seconds when exposed to non-shielded welding arcs or other sources of intense ultraviolet light. Nevertheless, the inflicted harm is often not immediately obvious.{{citation needed|date=February 2024}}


Sunburn is usually not immediately obvious. After being burnt, skin may turn red 2 to 6 hours later. Pain is worst 6 to 48 hours afterward. The burn continues to develop for 24 to 72 hours after the incident. Skin peeling begins 3 to 8 days after the burn occurs. Common outcomes include tenderness, [[pain]], [[edema]], red and/or peeling skin, rash, nausea and [[fever]]. Sunburns may be first- or second-degree [[burn (injury)|burns]].
After sun exposure, the skin may turn red in as little as 30 minutes, but sunburn usually takes 2 to 6 hours. Pain is usually strongest 6 to 48 hours after exposure. The burn continues to develop for 1 to 3 days, occasionally followed by peeling skin after 3 to 8 days. Some peeling and itching may continue for several weeks.{{citation needed|date=February 2023}}


===Skin cancer===
Minor sunburns typically cause nothing more than slight redness and tenderness to the affected area. In more serious cases blistering can occur. Extreme sunburns can be painful to the point of debilitation and may require hospital admission.
Ultraviolet radiation causes sunburns and increases the risk of three types of skin cancer: [[melanoma]], [[basal-cell carcinoma]] and [[squamous-cell carcinoma]].<ref name="Do sunscreens prevent skin cancer"/><ref name="Solar and ultraviolet radiation"/><ref name="Facts About Sunburn and Skin Cancer">[http://www.skincancer.org/prevention/sunburn/facts-about-sunburn-and-skin-cancer "Facts About Sunburn and Skin Cancer"] {{Webarchive|url=https://web.archive.org/web/20130602050703/http://www.skincancer.org/prevention/sunburn/facts-about-sunburn-and-skin-cancer |date=2 June 2013 }}, [[Skin Cancer Foundation]]</ref> Of greatest concern is that the melanoma risk increases dose-dependently proportional to the number of a person's lifetime cumulative episodes of sunburn.<ref>{{cite journal | vauthors = Dennis LK, Vanbeek MJ, Beane Freeman LE, Smith BJ, Dawson DV, Coughlin JA | title = Sunburns and risk of cutaneous melanoma: does age matter? A comprehensive meta-analysis | journal = Annals of Epidemiology | volume = 18 | issue = 8 | pages = 614–27 | date = August 2008 | pmid = 18652979 | pmc = 2873840 | doi = 10.1016/j.annepidem.2008.04.006 }}</ref> An estimated 1/3 of melanomas in the United States and Australia could be prevented with regular sunscreen use.<ref>{{cite journal | vauthors = Olsen CM, Wilson LF, Green AC, Biswas N, Loyalka J, Whiteman DC | title = How many melanomas might be prevented if more people applied sunscreen regularly? | journal = The British Journal of Dermatology | volume = 178 | issue = 1 | pages = 140–147 | date = January 2018 | pmid = 29239489 | doi = 10.1111/bjd.16079 | s2cid = 10914195 | url = https://www.research.manchester.ac.uk/portal/en/publications/how-many-melanomas-might-be-prevented-if-more-people-applied-sunscreen-regularly(93596881-2300-49b2-8d90-66bdc0767858).html | access-date = 13 December 2019 | archive-date = 7 August 2020 | archive-url = https://web.archive.org/web/20200807144454/https://www.research.manchester.ac.uk/portal/en/publications/how-many-melanomas-might-be-prevented-if-more-people-applied-sunscreen-regularly(93596881-2300-49b2-8d90-66bdc0767858).html | url-status = live }}</ref>


==Causes==
The major danger of sunburn is the increased risk of future [[skin cancer]]. At the cellular level, UVB light causes [[DNA]] damage which may be passed onto subsequent generations of a cell's progeny, leading to increased risk of skin cancer. Damaged cells die and release toxins which are responsible for nausea and fever. If many die, peeling may result. One incident of blistering sunburn doubles the risk of [[malignant melanoma]].
[[File:direct DNA damage.png|thumb|right| The cause of sunburn is the direct damage that a [[UVB]] [[photon]] can induce in [[DNA]] (left). One of the possible reactions from the excited state is the formation of a [[thymine]]-thymine [[cyclobutane]] [[Dimer (chemistry)|dimer]] (right).]]
Sunburn is caused by [[UV radiation]] from the Sun but may also result from artificial sources, such as [[tanning lamps]], [[welding]] arcs, or [[ultraviolet germicidal irradiation]]. It is the body's reaction to [[direct DNA damage]] from UVB light. This damage is mainly the formation of a [[Pyrimidine dimers|thymine dimer]]. The damage is recognized by the body, which then triggers several defense mechanisms, including DNA repair to revert the damage, [[apoptosis]] and peeling to remove irreparably damaged skin cells, and increased melanin production to prevent future damage.<ref name=":1" />


Melanin readily absorbs UV wavelength light, acting as a photoprotectant. By preventing UV photons from disrupting chemical bonds, melanin inhibits both the direct alteration of DNA, as well as the generation of [[Radical (chemistry)#In biology|free radicals]], to prevent them from indirectly damaging DNA. However, human [[melanocyte]]s contain over 2,000 [[genome|genomic sites]] that are highly sensitive to [[ultraviolet|UV]], and such sites can be up to 170-fold more sensitive to UV induction of cyclobutane [[pyrimidine dimer]]s than the average site<ref>{{cite journal | doi=10.1073/pnas.1907860116 | title=Genomic sites hypersensitive to ultraviolet radiation | year=2019 | last1=Premi | first1=Sanjay | last2=Han | first2=Lynn | last3=Mehta | first3=Sameet | last4=Knight | first4=James | last5=Zhao | first5=Dejian | last6=Palmatier | first6=Meg A. | last7=Kornacker | first7=Karl | last8=Brash | first8=Douglas E. | journal=Proceedings of the National Academy of Sciences | volume=116 | issue=48 | pages=24196–24205 | pmid=31723047 | pmc=6883822 | bibcode=2019PNAS..11624196P | doi-access=free }}</ref> These sensitive sites often occur at biologically significant locations near [[gene]]s.
==Increased risk==


Sunburn causes an [[inflammation]] process that includes the production of [[prostanoid]]s and [[bradykinin]]. These chemical compounds increase sensitivity to heat by reducing the threshold of heat receptor ([[TRPV1]]) activation from {{convert|109|°F}} to {{convert|85|°F}}.<ref>{{cite book |url=http://www.scientificamerican.com/article/how-we-sense-the-heat-of-chili-peppers-and-the-cool-of-menthol-excerpt/ |title=Touch: The Science of Hand, Heart and Mind |first=David J. |last=Linden |name-list-style=vanc |publisher=Viking |date=2015 |access-date=1 March 2015 |archive-date=15 October 2021 |archive-url=https://web.archive.org/web/20211015185627/https://www.scientificamerican.com/article/how-we-sense-the-heat-of-chili-peppers-and-the-cool-of-menthol-excerpt/ |url-status=live }}</ref> The pain may be caused by the overproduction of a protein called [[CXCL5]], which activates nerve fibers.<ref>{{cite journal | vauthors = Dawes JM, Calvo M, Perkins JR, Paterson KJ, Kiesewetter H, Hobbs C, Kaan TK, Orengo C, Bennett DL, McMahon SB | title = CXCL5 mediates UVB irradiation-induced pain | journal = Science Translational Medicine | volume = 3 | issue = 90 | pages = 90ra60 | date = July 2011 | pmid = 21734176 | pmc = 3232447 | doi = 10.1126/scitranslmed.3002193 }}</ref>
The risk of sunburn can be increased by some [[pharmaceutical]] products that can sensitise a person taking them to UV radiation. Some [[antibiotic]]s, [[contraceptive]]s, and [[tranquillizer]]s have this effect.


[[Fitzpatrick scale|Skin type]] determines the ease of sunburn. People with lighter skin tones and limited capacity to develop a tan after UV radiation exposure have a greater risk of sunburn. Fitzpatrick's Skin phototypes classification describes the normal variations of skin responses to UV radiation. Persons with type I skin have the greatest capacity to sunburn, and type VI have the least capacity to burn. However, all skin types can develop sunburn.<ref name=Fit2013/>
[[Sun tanning|Suntans]], which naturally develop in some individuals as a protective mechanism against the sun, are viewed by many in the Western world as desirable. This has led to increases in sunburn incidences and in [[sunbed|solarium]] popularity as individuals attempt to tan.


[[Thomas B. Fitzpatrick|Fitzpatrick's]] skin phototypes:
In recent years, the incidence and severity of sunburn has increased worldwide, especially in the southern hemisphere, because of damage to the [[ozone layer]] due to [[CFC]]s. Some are worried that [[ozone depletion]] and the seasonal [[ozone hole]] has led to dangerously high levels of UV light.
* Type 0: [[Albinism in humans|Albino]]
* Type I: Pale [[white skin]], burns easily, does not [[Sun tanning|tan]]
* Type II: White skin, burns easily, tans with difficulty
* Type III: White skin, may burn, but eventually tans easily
* Type IV: [[Olive skin|Light brown/olive skin]], hardly burns, tans easily
* Type V: [[Brown skin]], usually does not burn, tans easily
* Type VI: [[Black skin]], very unlikely to burn, becomes darker with UV radiation exposure<ref>{{Cite book|title=Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology|publisher=McGraw Hill|year=2017|editor-last=Wolff|editor-first=K|edition=8th|location=New York, NY|chapter=PHOTOSENSITIVITY, PHOTO-INDUCED DISORDERS, AND DISORDERS BY IONIZING RADIATION|access-date=20 March 2018|chapter-url=http://accessmedicine.mhmedical.com/content.aspx?bookid=2043&sectionid=154898268|archive-date=21 March 2018|archive-url=https://web.archive.org/web/20180321063319/http://accessmedicine.mhmedical.com/content.aspx?bookid=2043&sectionid=154898268|url-status=live}}</ref>


Age also affects how skin reacts to the sun. Children younger than six and adults older than sixty are more sensitive to sunlight.<ref name="WebMD2" />
A 2003 study found that 36% of US adults have a sunburn at least once a year; one study found 50% of Canadians to have been burnt in the two months prior to the study.


Certain genetic conditions, for example, [[xeroderma pigmentosum]], increase a person's susceptibility to sunburn and subsequent skin cancers. These conditions involve defects in DNA repair mechanisms which decrease the ability to repair DNA damaged by UV radiation.<ref>{{Cite book|url=https://www.ncbi.nlm.nih.gov/books/NBK1397/|title=GeneReviews®|last1=Kraemer|first1=Kenneth H.|last2=DiGiovanna|first2=John J.|chapter=Xeroderma Pigmentosum|name-list-style=vanc|date=1993|publisher=University of Washington, Seattle|editor-last=Adam|editor-first=Margaret P.|location=Seattle (WA)|pmid=20301571|editor-last2=Ardinger|editor-first2=Holly H.|editor-last3=Pagon|editor-first3=Roberta A.|editor-last4=Wallace|editor-first4=Stephanie E.|editor-last5=Bean|editor-first5=Lora JH|editor-last6=Stephens|editor-first6=Karen|editor-last7=Amemiya|editor-first7=Anne|access-date=23 March 2018|archive-date=17 April 2021|archive-url=https://web.archive.org/web/20210417120234/http://www.ncbi.nlm.nih.gov/books/NBK1397/|url-status=live}}</ref>
==Protection==


===Medications===
It is advisable to wear long-sleeved garments and wide-brimmed [[hat]]s or use an [[umbrella]] when in the sun. Minimisation of sun exposure between the hours of 10 am to 3 pm is also recommended.
The risk of sunburn can be increased by [[pharmaceutical]] products that sensitize users to UV radiation. Certain [[antibiotic]]s, oral [[contraceptive]]s, [[antidepressant]]s, [[acne medication]]s, and [[tranquillizer]]s have this effect.<ref name="factsheet">[https://web.archive.org/web/20080516025810/http://www.fact-sheets.com/health/avoiding_sun_damage/ "Avoiding Sun-Related Skin Damage"]. Fact-Sheets.com. 2004. Retrieved 3 January 2015.</ref>


===UV intensity===
Commercial preparations are available that block UV light, known as [[sunscreen]]s. Sometimes called suncreams or sunblocks, they have a Sun Protection Factor (''[[SPF]]'') rating, based on the sunblock's ability to reduce the UVB radiation at the skin: the higher the SPF rating, the greater the protection. A sunscreen rated SPF15 blocks 93.3% UVB and an SPF30 rated sunscreen blocks 96.7%. It is best to use a broad spectrum sunscreen in order to protect against both UVA and UVB radiation. It is prudent to use waterproof formulations if one plans to engage in water-based activities.
The [[UV Index]] indicates the risk of sunburn at a given time and location. Contributing factors include:<ref name="WebMD2">{{cite web |url=http://www.webmd.com/skin-problems-and-treatments/tc/sunburn-topic-overview |title=Sunburn – Topic Overview |publisher=Healthwise |date=15 November 2013 |access-date=29 November 2014 |archive-date=30 September 2017 |archive-url=https://web.archive.org/web/20170930062741/http://www.webmd.com/skin-problems-and-treatments/tc/sunburn-topic-overview |url-status=live }}</ref>
# The time of day. In most locations, the sun's rays are strongest between approximately 10&nbsp;am and 4&nbsp;pm [[daylight saving time]].<ref>{{Cite web | url = https://www.fda.gov/radiation-emittingproducts/radiationemittingproductsandprocedures/tanning/ucm116425.htm | title = Tanning – Ultraviolet (UV) Radiation | work = Health Center for Devices and Radiological | publisher = United States Food and Drug Administration | access-date = 19 May 2017 | archive-date = 23 May 2017 | archive-url = https://web.archive.org/web/20170523181154/https://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/Tanning/ucm116425.htm | url-status = live }}</ref>
# Cloud cover. Clouds partially block UV, but even on an overcast day, a significant percentage of the sun's damaging UV radiation can pass through clouds.<ref name=WHO>{{cite web |publisher=[[World Health Organization]] |year=2002 |title=Global Solar UV Index: A Practical Guide |url=https://www.who.int/uv/publications/en/UVIGuide.pdf |access-date=2 January 2015 |quote=Up to 80% of solar UV radiation can penetrate light cloud cover. |archive-date=27 November 2014 |archive-url=https://web.archive.org/web/20141127003008/http://www.who.int/uv/publications/en/UVIGuide.pdf |url-status=live }}</ref><ref name=uvicalc>{{cite web |publisher=[[EPA]] |year=2012 |url=http://www.epa.gov/sunwise/uvicalc.html |title=How UV Index Is Calculated |access-date=2 January 2015 |quote=Clear skies allow virtually 100% of UV to pass through, scattered clouds transmit 89%, broken clouds transmit 73%, and overcast skies transmit 31%. |archive-date=16 February 2015 |archive-url=https://web.archive.org/web/20150216034357/http://www.epa.gov/sunwise/uvicalc.html |url-status=live }}</ref>
# Proximity to reflective surfaces, such as water, sand, concrete, snow, and ice. All of these reflect the sun's rays and can cause sunburns.
# The season of the year. The Sun's position in late spring and early summer can cause a more-severe sunburn.
# Altitude. At a higher altitude, it is easier to become burnt, because there is less of the Earth's atmosphere to block the sunlight. UV exposure increases about 4% for every 1000&nbsp;ft (305 m) gain in elevation.
# Proximity to the equator (latitude). Between the polar and tropical regions, the closer to the equator, the more direct sunlight passes through the atmosphere over a year. For example, the southern United States gets fifty percent more sunlight than the northern United States.


[[File:UV Diurnal Erythemal Dose Rate Per Latitude graph.png|thumb|right|Erythemal dose rate at three Northern latitudes. (Divide by 25 to obtain the UV Index.) Source: NOAA.]]
Sunscreen should have a SPF rating of at least 15. It should be applied half an hour before going out and reapplied every two hours thereafter.
Because of variations in the intensity of UV radiation passing through the atmosphere, the risk of sunburn increases with proximity to the [[tropics|tropic latitudes]], located between 23.5° north and south latitude. All else being equal (e.g., cloud cover, [[ozone layer]], [[terrain]], etc.), each location within the tropic or [[polar region]]s receives approximately the same amount of UV radiation over a year. In the [[Temperate|temperate zones]] between 23.5° and 66.5°, UV radiation varies substantially by latitude and season. The higher the latitude, the lower the intensity of the UV rays. Sun intensity in the northern hemisphere is greatest during May, June and July{{Emdash}}and in the southern hemisphere, November, December and January. On a minute-by-minute basis, the amount of UV radiation depends on the Sun's angle. Ultraviolet radiation is easily determined by the height [[ratio]] of any object to the size of its [[shadow]]. Height is measured parallel to the Earth's gravitational field and the projected shadow is measured on a flat, level surface. For objects wider than skulls or poles, the height and length are best measured relative to the same occluding edge. The most significant risk is at [[solar noon]] when shadows are at their minimum, and the Sun's radiation passes most directly through the atmosphere. Regardless of one's latitude (assuming no other variables), equal shadow lengths mean equal amounts of UV radiation.{{citation needed|date=February 2024}}


The skin and eyes are most sensitive to damage by UV at 265–275&nbsp;nm wavelength, which is in the lower UVC band that is rarely encountered except from artificial sources like welding arcs. Longer wavelengths of UV radiation cause most sunburn because those wavelengths are more prevalent in ground-level sunlight.{{citation needed|date=February 2024}}
Eyes should not be neglected, and wrap-around [[sunglasses]] which block UV light should also be worn. UV light has been implicated in [[pterygium]] and [[cataract]] development.


===Ozone depletion===
When one is exposed to any artificial source of occupational UV, special protective clothing (for example, [[welding mask]]s) should be worn.
In recent decades, the incidence and severity of sunburn have increased worldwide, partly because of chemical damage to the atmosphere's ozone layer. Between the 1970s and the 2000s, average stratospheric ozone decreased by approximately 4%, contributing an approximate 4% increase to the average UV intensity at the Earth's surface. [[Ozone depletion]] and the seasonal "ozone hole" have led to much larger changes in some locations, especially in the southern hemisphere.<ref>{{cite book |title=Scientific Assessment of Ozone Depletion: 2010 |publisher=World Meteorological Organization |chapter=Twenty Questions and Answers About the Ozone Layer |chapter-url=http://acdb-ext.gsfc.nasa.gov/Documents/O3_Assessments/Docs/WMO_2010/Q2_QA.pdf |date=2011 |access-date=13 March 2015 |archive-date=1 April 2014 |archive-url=https://web.archive.org/web/20140401103337/http://acdb-ext.gsfc.nasa.gov/Documents/O3_Assessments/Docs/WMO_2010/Q2_QA.pdf |url-status=live }}</ref>


== Treatment ==
===Tanning===
[[Sun tanning|Suntans]], which naturally develop in some individuals as a protective mechanism against the sun, are viewed by most in the Western world as desirable.<ref name="WebMDSunTan">{{cite web |url=http://www.webmd.com/hw/health_guide_atoz/sts15336.asp?navbar=hw82391 |title=Suntan |access-date=26 August 2006 |publisher=Healthwise |date=27 March 2005}}</ref> Tanning has led to an increased exposure to UV radiation from both the natural sun and [[tanning lamp]]s. Suntans can provide a modest [[sun protection factor]] (SPF) of 3, meaning that tanned skin would tolerate up to three times the UV exposure as pale skin.<ref>{{cite web |url=http://www.surgeongeneral.gov/library/calls/prevent-skin-cancer/call-to-action-prevent-skin-cancer.pdf |publisher=U.S. Department of Health and Human Services |title=The Surgeon General's Call to Action to Prevent Skin Cancer |year=2014 |page=20 |quote=A UVB-induced tan provides minimal sun protection, equivalent to an SPF of about 3. |access-date=17 August 2016 |archive-date=26 November 2014 |archive-url=https://web.archive.org/web/20141126233100/http://www.surgeongeneral.gov/library/calls/prevent-skin-cancer/call-to-action-prevent-skin-cancer.pdf |url-status=live }}</ref>


Sunburns associated with indoor tanning can be severe.<ref>{{cite journal | vauthors = Guy GP, Watson M, Haileyesus T, Annest JL | title = Indoor tanning-related injuries treated in a national sample of US hospital emergency departments | journal = JAMA Internal Medicine | volume = 175 | issue = 2 | pages = 309–11 | date = February 2015 | pmid = 25506731 | pmc = 4593495 | doi = 10.1001/jamainternmed.2014.6697 }}</ref>
There are numerous topical skin products that can relieve the pain of a sunburn and speed up the healing process. However, it is best advised never to cover a sunburn that is blistered or open with any sort of cream, gel, or ointment as it may cause the wound to be infected.


The World Health Organization, American Academy of Dermatology, and the [[Skin Cancer Foundation]] have recommended avoiding artificial UV sources such as tanning beds. Suntans are not recommended as a form of sun protection.<ref>{{Cite web|url=https://www.skincancer.org/prevention|title=Prevention - SkinCancer.org|website=skincancer.org|language=en-US|access-date=30 March 2018|archive-date=30 March 2018|archive-url=https://web.archive.org/web/20180330143741/https://www.skincancer.org/prevention|url-status=live}}</ref><ref>{{Cite web|url=https://www.aad.org/media/stats/prevention-and-care|title=Dangers of indoor tanning {{!}} American Academy of Dermatology|website=www.aad.org|access-date=30 March 2018|archive-date=30 March 2018|archive-url=https://web.archive.org/web/20180330211233/https://www.aad.org/media/stats/prevention-and-care|url-status=live}}</ref><ref>{{Cite web|url=https://www.who.int/uv/publications/artificial-tanning-devices/en/|archive-url=https://web.archive.org/web/20170629111833/http://www.who.int/uv/publications/artificial-tanning-devices/en/|url-status=dead|archive-date=29 June 2017|title=WHO {{!}} Artificial tanning devices: public health interventions to manage sunbeds|website=WHO|access-date=30 March 2018}}</ref>
The symptoms of milder sunburn can be treated with an [[antipruritic]] such as [[Calamine Lotion]].


== Diagnosis ==
The thick mucilaginous gel on an ''[[aloe|Aloe vera]]'' plant or aloe-based products are popular treatments that heal the burn and relieve pain.
[[File:Sunburned_knee.png|thumb|305x305px|A sunburned leg below the [[shorts]] line]]


=== Differential diagnosis ===
Regular white [[vinegar]] and apple cider vinegar have often been touted for their usefulness in treating sunburns and preventing blistering and peeling.
The differential diagnosis of sunburn includes other skin pathology induced by UV radiation, including photoallergic reactions, phototoxic reactions to topical or systemic medications, and other dermatologic disorders that are aggravated by exposure to sunlight. Considerations for diagnosis include duration and intensity of UV exposure, topical or systemic medication use, history of dermatologic disease, and nutritional status.
* Phototoxic reactions: Non-immunological response to sunlight interacting with certain drugs and chemicals in the skin which resembles an exaggerated sunburn. Common medications that may cause a phototoxic reaction include [[amiodarone]], [[dacarbazine]], [[fluoroquinolone]]s, [[5-fluorouracil]], [[furosemide]], [[nalidixic acid]], [[phenothiazines]], [[psoralens]], [[retinoid]]s, [[sulfonamide]]s, [[sulfonylurea]]s, [[tetracycline]]s, [[thiazide]]s, and [[vinblastine]].<ref name=":0">{{cite book|title=Harrison's principles of internal medicine.|last1=Kasper|first1=Dennis L.|last2=Fauci|first2=Anthony S.|last3=Hauser|first3=Stephen L.|last4=Longo|first4=Dan L.|last5=Jameson|first5=J. Larry|last6=Loscalzo|first6=Joseph|isbn=978-0-07-180215-4|edition=19th|publisher = McGraw Hill |location=New York|oclc=893557976|name-list-style=vanc|date=8 April 2015}}</ref>
* Photoallergic reactions: Uncommon immunological response to sunlight interacting with certain drugs and chemicals in the skin. When in an excited state by UVR, these drugs and chemicals form free radicals that react to form functional antigens and induce a Type IV hypersensitivity reaction. These drugs include 6-[[methylcoumarin]], [[aminobenzoic acid]] and esters, [[chlorpromazine]], [[promethazine]], [[diclofenac]], sulfonamides, and sulfonylureas. Unlike phototoxic reactions which resemble exaggerated sunburns, photoallergic reactions can cause intense itching and can lead to thickening of the skin.<ref name=":0" />
* Phytophotodermatitis: UV radiation induces skin inflammation after contact with certain plants (including limes, celery, and [[meadow grass]]). Causes pain, redness, and blistering of the skin in the distribution of plant exposure.<ref name=Fit2013>{{cite book | title=Fitzpatrick's color atlas and synopsis of clinical dermatology|date=2013|publisher=McGraw-Hill Medical| first1 = Klaus | last1 = Wolff | first2 = Richard | last2 = Johnson | first3 = Arturo | last3 = Saavedra | name-list-style = vanc | isbn = 978-0-07-179302-5 | edition = 7th | location = New York | oclc = 813301093 }}</ref>
* Polymorphic light eruption: Recurrent abnormal reactions to UVR present in various ways, including pink-to-red bumps, blisters, plaques and urticaria.<ref name=Fit2013 />
* Solar urticaria: A rare allergic reaction to the sun that occurs within minutes of exposure and fades within hours.<ref name=Fit2013 />
* Other skin diseases exacerbated by sunlight: Several dermatologic conditions can increase in severity with exposure to UVR. These include systemic [[lupus erythematosus]] (SLE), [[dermatomyositis]], acne, [[atopic dermatitis]], and [[rosacea]].<ref name=Fit2013 />
Additionally, since sunburn is a type of [[radiation burn]],<ref>{{Cite web|url=https://www.webmd.com/first-aid/types-degrees-burns|title=What Are the Types and Degrees of Burns?|access-date=7 June 2019|archive-date=7 June 2019|archive-url=https://web.archive.org/web/20190607142248/https://www.webmd.com/first-aid/types-degrees-burns|url-status=live}}</ref><ref>{{Cite web|url=https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P00317|title=Sunburn – Health Encyclopedia – University of Rochester Medical Center|access-date=7 June 2019|archive-date=8 June 2019|archive-url=https://web.archive.org/web/20190608222043/https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P00317|url-status=live}}</ref> it can initially hide a severe exposure to [[radioactivity]]. Excess radiation exposure may result in [[acute radiation syndrome]] or other radiation-induced illnesses, especially in sunny conditions. For instance, the difference between the [[erythema]] caused by sunburn and other radiation burns is not immediately obvious. Symptoms common to [[heat illness]] and the prodromic stage of acute radiation syndrome like nausea, vomiting, fever, weakness/fatigue, dizziness or seizure can add to further diagnostic confusion.<ref>{{Cite web |date=23 October 2020 |title=Acute Radiation Syndrome &#124; CDC |url=https://www.cdc.gov/nceh/radiation/emergencies/ars.htm?CDC_AA_refVal=https%3A%2F%2Femergency.cdc.gov%2Fradiation%2Fars.asp |access-date=7 June 2019 |archive-date=8 June 2019 |archive-url=https://web.archive.org/web/20190608222042/https://www.cdc.gov/nceh/radiation/emergencies/ars.htm?CDC_AA_refVal=https%253A%252F%252Femergency.cdc.gov%252Fradiation%252Fars.asp |url-status=live }}</ref>


==Prevention==
Other more unusual treatments involve the application of [[lavender oil]], [[tea]] (cooled), [[yogurt]], [[St. John's wort]], or [[cucumbers]] to the burnt skin.
[[File:Erythemal action spectrum.svg|thumb|right|Sunburn effect (as measured by the [[UV Index]]) is the product of the sunlight spectrum at the Earth's surface (radiation intensity) and the erythemal action spectrum (skin sensitivity). Long-wavelength UV is more prevalent, but each milliwatt at 295 nm produces almost 100 times more sunburn than at 315 nm.]]
[[File:Sun burn.JPG|thumb|Skin peeling on the upper arm as a result of sunburn – the destruction of lower layers of the [[epidermis]] causes rapid loss of the top layers]]
[[File:Sunburn - (20190727170341).jpg|thumb|[[Tanned skin|Tanning]] of the forearm (visible darkening of the skin) after extended sun exposure]]
The most effective way to prevent sunburn is to reduce the amount of UV radiation reaching the skin. The World Health Organization, American Academy of Dermatology, and Skin Cancer Foundation recommend the following measures to prevent excessive UV exposure and skin cancer:<ref name="Sun protection">{{Cite web|url=https://www.who.int/uv/sun_protection/en/|title=Sun protection|website=World Health Organization|language=en-GB|access-date=28 March 2018|archive-date=22 March 2018|archive-url=https://web.archive.org/web/20180322153809/http://www.who.int/uv/sun_protection/en/|url-status=live}}</ref><ref>{{Cite web|url=https://www.skincancer.org/prevention/sun-protection/prevention-guidelines|title=Prevention Guidelines - SkinCancer.org|website=skincancer.org|language=en-US|access-date=28 March 2018|archive-date=29 March 2018|archive-url=https://web.archive.org/web/20180329054204/https://www.skincancer.org/prevention/sun-protection/prevention-guidelines|url-status=live}}</ref><ref>{{Cite web|url=https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/prevent|title=Prevent skin cancer {{!}} American Academy of Dermatology|website=www.aad.org|access-date=28 March 2018|archive-date=14 May 2018|archive-url=https://web.archive.org/web/20180514075709/https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/prevent|url-status=live}}</ref>
* Limiting sun exposure between the hours of 10 am and 4 pm, when UV rays are the strongest
* Seeking shade when UV rays are most intense
* Wearing sun-protective clothing, including a wide-brim hat, sunglasses, and tightly woven, loose-fitting clothing
* Using sunscreen
* Avoiding tanning beds and artificial UV exposure


=== UV intensity ===
Skin treatments aside, the pain from a sunburn is often best treated with an [[analgesic]] such as [[acetaminophen]] or [[ibuprofen]]. Additional relief may be found by putting a cool, wet towel over the affected area.
The strength of sunlight is published in many locations as a [[UV Index]]. Sunlight is generally strongest when the Sun is close to the highest point in the sky. Due to time zones and daylight saving time, this is not necessarily at 12 pm, but often one to two hours later. Seeking shade using umbrellas and canopies can reduce UV exposure, but does not block all UV rays. The WHO recommends following the shadow rule: "Watch your shadow – Short shadow, seek shade!"<ref name="Sun protection"/>


=== Sunscreen ===
Using tomato on the skin is a more painful way of treating the burn, but is mostly effective.
Commercial preparations that block UV light are known as [[sunscreens]] or sunblocks. They have a [[sun protection factor]] (SPF) rating based on the sunblock's ability to suppress sunburn: The higher the SPF rating, the lower the amount of direct DNA damage. The stated protection factors are correct only if 2&nbsp;mg of sunscreen is applied per square cm of exposed skin translates into about 28 mL (1&nbsp;oz) to cover the whole body of an adult male. The recommended dose is much more than many people use in practice.<ref>{{cite journal | vauthors = Faurschou A, Wulf HC | title = The relation between sun protection factor and amount of suncreen applied in vivo | journal = The British Journal of Dermatology | volume = 156 | issue = 4 | pages = 716–9 | date = April 2007 | pmid = 17493070 | doi = 10.1111/j.1365-2133.2006.07684.x | s2cid = 22599824 }}</ref> Sunscreens function as chemicals such as [[oxybenzone]] and [[dioxybenzone]] (organic sunscreens) or opaque materials such as [[zinc oxide]] or [[titanium oxide]] (inorganic sunscreens) that mainly absorb UV radiation. Chemical and mineral sunscreens vary in the wavelengths of UV radiation blocked. Broad-spectrum sunscreens contain filters that protect against UVA radiation as well as UVB. Although UVA radiation does not primarily cause sunburn, it contributes to [[Photoaging|skin aging]] and increases skin cancer risk.{{citation needed|date=February 2024}}
Ice provides immediate relief; however, once removed, discomfort may follow. Also to note is the common use of almond milk which is particularly soothing to children. Avocado-based moisturing lotions have proven as effective as standard pharmaceutical aftersun treatments in cooling the burn, reducing the edema and restoring elasticity to the burnt skin if applied within 24 hours of the burn.


Sunscreen is effective and thus recommended for preventing [[melanoma]]<ref name="SunM">{{cite journal|vauthors=Kanavy HE, Gerstenblith MR|date=December 2011|title=Ultraviolet radiation and melanoma|journal=Seminars in Cutaneous Medicine and Surgery|volume=30|issue=4|pages=222–8|doi=10.1016/j.sder.2011.08.003|doi-broken-date=18 November 2024 |pmid=22123420}}</ref> and [[squamous cell carcinoma]].<ref name="SunS">{{cite journal|vauthors=Burnett ME, Wang SQ|date=April 2011|title=Current sunscreen controversies: a critical review|journal=Photodermatology, Photoimmunology & Photomedicine|volume=27|issue=2|pages=58–67|doi=10.1111/j.1600-0781.2011.00557.x|pmid=21392107|doi-access=free}}</ref> There is little evidence that it is effective in preventing [[basal cell carcinoma]].<ref>{{cite journal|vauthors=Kütting B, Drexler H|date=December 2010|title=UV-induced skin cancer at workplace and evidence-based prevention|journal=International Archives of Occupational and Environmental Health|volume=83|issue=8|pages=843–54|doi=10.1007/s00420-010-0532-4|pmid=20414668|bibcode=2010IAOEH..83..843K |s2cid=40870536}}</ref> Typical use of sunscreen does not usually result in [[vitamin D deficiency]], but extensive usage may.<ref>{{cite journal|vauthors=Norval M, Wulf HC|date=October 2009|title=Does chronic sunscreen use reduce vitamin D production to insufficient levels?|journal=The British Journal of Dermatology|volume=161|issue=4|pages=732–6|doi=10.1111/j.1365-2133.2009.09332.x|pmid=19663879|s2cid=12276606}}</ref>
==Windburn==


==== Recommendations ====
On cold days, people often refer to their sunburn as a windburn. Windburn is actually a distinct condition whereby the top layer of oil is removed from the skin, causing excessive dryness that leads to redness and a burning feeling. However, people commonly believe that any burn on a cold day is windburn. In fact, since sunburn is a result of UV light rather than heat, hot temperatures are not necessary. This mistake is frequently made while skiing, where sunburn can occur in very cold temperatures since the UV light is reflecting off the snow and higher altitudes provide less atmosphere to block UV.
Research has shown that the best sunscreen protection is achieved by application 15 to 30 minutes before exposure, followed by one reapplication 15 to 30 minutes after exposure begins. Further reapplication is necessary after activities such as swimming, sweating, and rubbing.<ref>{{cite journal | vauthors = Diffey BL | title = When should sunscreen be reapplied? | journal = Journal of the American Academy of Dermatology | volume = 45 | issue = 6 | pages = 882–5 | date = December 2001 | pmid = 11712033 | doi = 10.1067/mjd.2001.117385 }}</ref> Recommendations are product dependent varying from 80 minutes in water to hours based on the indications and protection shown on the label. The American Academy of Dermatology recommends the following criteria in selecting a sunscreen:<ref>{{Cite web|url=https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/prevent/how-to-select-a-sunscreen|title=How to select a sunscreen {{!}} American Academy of Dermatology|website=www.aad.org|access-date=28 March 2018|archive-date=29 March 2018|archive-url=https://web.archive.org/web/20180329054240/https://www.aad.org/public/spot-skin-cancer/learn-about-skin-cancer/prevent/how-to-select-a-sunscreen|url-status=live}}</ref>
* Broad spectrum: protects against both UVA and UVB rays
* SPF 30 or higher
* Water resistant: sunscreens are classified as water resistant based on time, either 40 minutes, 80 minutes, or not water resistant


==Animals==
===Eyes===
The eyes are also sensitive to sun exposure at about the same UV wavelengths as skin; [[snow blindness]] is sunburn of the cornea. Wrap-around [[sunglasses]] or the use by spectacle-wearers of [[glasses]] that block UV light reduce harmful radiation. UV light has been implicated in the development of age-related [[macular degeneration]],<ref>{{cite journal | vauthors = Glazer-Hockstein C, Dunaief JL | title = Could blue light-blocking lenses decrease the risk of age-related macular degeneration? | journal = Retina | volume = 26 | issue = 1 | pages = 1–4 | date = January 2006 | pmid = 16395131 | doi = 10.1097/00006982-200601000-00001 }}</ref> [[Pterygium (conjunctiva)|pterygium]]<ref name=Solomon2006>{{cite journal | vauthors = Solomon AS | title = Pterygium | journal = The British Journal of Ophthalmology | volume = 90 | issue = 6 | pages = 665–6 | date = June 2006 | pmid = 16714259 | pmc = 1860212 | doi = 10.1136/bjo.2006.091413 }}</ref> and [[cataract]]s.<ref name=Neale2003>{{cite journal | vauthors = Neale RE, Purdie JL, Hirst LW, Green AC | title = Sun exposure as a risk factor for nuclear cataract | journal = Epidemiology | volume = 14 | issue = 6 | pages = 707–12 | date = November 2003 | pmid = 14569187 | doi = 10.1097/01.ede.0000086881.84657.98 | s2cid = 40041207 | doi-access = free }}</ref> Concentrated clusters of melanin, commonly known as [[freckles]], are often found within the iris.


The tender skin of the [[eyelid]]s can also become sunburned and can be especially irritating.{{citation needed|date=February 2024}}
Many animals can also suffer from sunburn, however most animals are protected by a layer of dense fur. Despite myths stating that only hippopotami and pigs can be affected by sunburn, almost all animals, given the right situation can - even fish can suffer sunburn (though pigs and hippopotami are more prone due their hairless skin producing less oil - a natural sun protector).


== See also ==
=== Lips ===
The [[Chapped Lips|lips can become chapped]] (cheilitis) by sun exposure. Sunscreen on the lips does not have a pleasant taste and might be removed by saliva. Some [[lip balm]]s (ChapSticks) have SPF ratings and contain sunscreens.{{citation needed|date=February 2024}}
* [[Sun unit]] unit of weighted sun intensity
* [[Hyperthermia]] (heat stroke) is another health hazard resulting from excessive exposure to the sun.


==External links==
=== Feet ===
The skin of the feet is often tender and protected, so sudden prolonged exposure to UV radiation can be particularly painful and damaging to the top of the foot. Protective measures include sunscreen, socks, or swimwear that covers the foot.


===Diet===
*[http://www.fact-sheets.com/health/avoiding_sun_damage/ Sun Protection Tips]
Dietary factors influence susceptibility to sunburn, recovery from sunburn, and risk of secondary complications. Several dietary [[antioxidants]], including essential vitamins, are effective in protecting against sunburn and skin damage associated with ultraviolet radiation, in both human and animal studies. Supplementation with [[Vitamin C]] and [[Vitamin E]] was shown in one study to reduce the amount of sunburn after a controlled amount of UV exposure.<ref name="Eberlein-KönigPlaczek1998">{{cite journal | vauthors = Eberlein-König B, Placzek M, Przybilla B | title = Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E) | journal = Journal of the American Academy of Dermatology | volume = 38 | issue = 1 | pages = 45–8 | date = January 1998 | pmid = 9448204 | doi = 10.1016/S0190-9622(98)70537-7 }}</ref>
*[http://www.fact-sheets.com/health/kids_sun_protection/ Protecting Kids from the Sun]
A review of scientific literature through 2007 found that [[beta carotene]] (Vitamin A) supplementation had a protective effect against sunburn. The effects of beta carotene were only evident in the long-term, with studies of supplementation for periods less than ten weeks in duration failing to show any effects.<ref name="KöpckeKrutmann2008">{{cite journal | vauthors = Köpcke W, Krutmann J | title = Protection from sunburn with beta-Carotene—a meta-analysis | journal = Photochemistry and Photobiology | volume = 84 | issue = 2 | pages = 284–8 | year = 2008 | pmid = 18086246 | doi = 10.1111/j.1751-1097.2007.00253.x | s2cid = 86776862 | doi-access = free }}</ref> There is also evidence that common foods may have some protective ability against sunburn if taken for a period before exposure.<ref>{{cite journal | vauthors = Stahl W, Sies H | title = Carotenoids and flavonoids contribute to nutritional protection against skin damage from sunlight | journal = Molecular Biotechnology | volume = 37 | issue = 1 | pages = 26–30 | date = September 2007 | pmid = 17914160 | doi = 10.1007/s12033-007-0051-z | s2cid = 22417600 }}</ref><ref>{{Cite journal |pmc = 3583891|year = 2012|last1 = Schagen|first1 = S. K.|title = Discovering the link between nutrition and skin aging|journal = Dermato-Endocrinology|volume = 4|issue = 3|pages = 298–307|last2 = Zampeli|first2 = V. A.|last3 = Makrantonaki|first3 = E.|last4 = Zouboulis|first4 = C. C.|pmid = 23467449|doi = 10.4161/derm.22876}}</ref>
*[http://www.surviveoutdoors.com/reference/sunburn.asp Sunburn Information]
*[http://www.surviveoutdoors.com/emergency/sunburn.asp Sunburn Pictures]
*[http://www.nlm.nih.gov/medlineplus/ency/article/003227.htm Medline - Sunburn]
*[http://www.nlm.nih.gov/medlineplus/ency/article/000062.htm Medline - Sunburn First Aid]
*[http://www.sunsmart.com.au Sunsmart Victoria (Australia)]
*[http://www.ciesin.org/docs/001-540/001-540.html Influences of Ozone Depletion on Human and Animal Health]


== References ==
=== Protecting children ===
Babies and children are particularly susceptible to UV damage which increases their risk of both melanoma and non-melanoma skin cancers later in life. Children should not sunburn at any age, and protective measures can reduce their future risk of skin cancer.<ref>{{Cite web|url=https://www.skincancer.org/prevention/sun-protection/children|title=Children - SkinCancer.org|website=skincancer.org|date=13 September 2016|language=en-US|access-date=28 March 2018|archive-date=29 March 2018|archive-url=https://web.archive.org/web/20180329054301/https://www.skincancer.org/prevention/sun-protection/children|url-status=live}}</ref>
* Infants 0–6 months: Children under 6mo generally have skin too sensitive for sunscreen and protective measures should focus on avoiding excessive UV exposure by using window mesh covers, wide-brim hats, loose clothing that covers the skin, and reducing UV exposure between the hours of 10am and 4pm.
* Infants 6–12 months: Sunscreen can safely be used on infants this age. It is recommended to apply a broad-spectrum, water-resistant SPF 30+ sunscreen to exposed areas and avoid excessive UV exposure by using wide-brim hats and protective clothing.
* Toddlers and Preschool-aged children: Apply a broad-spectrum, water-resistant SPF 30+ sunscreen to exposed areas, use wide-brim hats and sunglasses, avoid peak UV intensity hours of 10 am - 4 pm and seek shade. Sun-protective clothing with an SPF rating can also provide additional protection.


=== Artificial UV exposure ===
*''Agar N, Halliday G, Barnetson R, Ananthaswamy H, Wheeler M, Jones A. The basal layer in human squamous tumors harbors more UVA than UVB fingerprint mutations: a role for UVA in human skin carcinogenesis. Proc Natl Acad Sci. 6 Apr 2004;101(14):4954-9.''
The WHO recommends that artificial UV exposure, including tanning beds, should be avoided as no safe dose has been established.<ref>{{Cite web|url=https://www.who.int/uv/publications/artificial-tanning-devices/en/|archive-url=https://web.archive.org/web/20170629111833/http://www.who.int/uv/publications/artificial-tanning-devices/en/|url-status=dead|archive-date=29 June 2017|title=WHO {{!}} Artificial tanning devices: public health interventions to manage sunbeds|website=WHO|access-date=28 March 2018}}</ref> Special protective clothing (for example, welding helmets/shields) should be worn when exposed to any artificial source of occupational UV. Such sources can produce UVC, an extremely carcinogenic wavelength of UV, which ordinarily is not present in normal sunlight, having been filtered out by the atmosphere.{{citation needed|date=February 2024}}


==Treatment==
*''Baron E, Fourtanier A, Compan D, Medaisko C, Cooper K, Stevens S. High ultraviolet A protection affords greater immune protection confirming that ultraviolet A contributes to photoimmunosuppression in humans. J Invest Dermatol. Oct 2003;121(4):869-75.''
The primary measure of treatment is avoiding further [[Health effects of sunlight exposure|exposure to the sun]]. The best treatment for most sunburns is time; most sunburns heal completely within a few weeks.


The [[American Academy of Dermatology]] recommends the following for the treatment of sunburn:<ref>{{Cite web|url=https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn|title=How to treat sunburn {{!}} American Academy of Dermatology|website=www.aad.org|access-date=28 March 2018|archive-date=20 March 2018|archive-url=https://web.archive.org/web/20180320170809/https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn|url-status=live}}</ref>
*''Hall H, Saraiya M, Thompson T, Hartman A, Glanz K, Rimer B. Correlates of Sunburn Experiences Among U.S. Adults: Results of the 2000 National Health Interview Survey. Public Health Reports 2003;118.''
* For pain relief, take cool baths or showers frequently.
* Use soothing [[moisturizers]] that contain [[aloe vera]] or soy.
* [[Anti-inflammatory medication]]s such as [[ibuprofen]] or [[aspirin]] can help with pain.
* Keep hydrated and drink extra water.
* Do not pop [[blisters]] on a sunburn; let them heal on their own instead.
* Protect sunburned skin (see: [[Sun protective clothing]] and [[Sunscreen]]) with loose clothing when going outside to prevent further damage while not irritating the sunburn.

[[Non-steroidal anti-inflammatory drugs]] (NSAIDs; such as [[ibuprofen]] or [[naproxen]]), and [[aspirin]] may decrease redness and pain.<ref>{{cite web |url=http://www.webmd.com/healthy-beauty/tc/sunburn-home-treatment |title=Sunburn – Home Treatment |publisher=Healthwise |date=15 November 2013 |access-date=29 November 2014 |url-status=dead |archive-url=https://web.archive.org/web/20120712121306/http://www.webmd.com/healthy-beauty/tc/sunburn-home-treatment |archive-date=12 July 2012 }}</ref><ref name="Sch2008" /> Local [[anesthetics]] such as [[benzocaine]], however, are contraindicated.<ref name="AAD" /> Schwellnus et al. state that [[topical steroid]]s (such as [[Cortisol|hydrocortisone cream]]) do not help with sunburns,<ref name=Sch2008/> although the [[American Academy of Dermatology]] says they can be used on especially sore areas.<ref name=AAD>{{cite web|url=https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn|title=How to treat sunburn|publisher=[[American Academy of Dermatology]]|language=en|access-date=26 June 2016|archive-date=20 March 2018|archive-url=https://web.archive.org/web/20180320170809/https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn|url-status=live}}</ref> While [[lidocaine]] cream (a local anesthetic) is often used as a sunburn treatment, there is little evidence for the effectiveness of such use.<ref>{{cite book|last1=Arndt|first1=Kenneth A.|last2=Hsu|first2=Jeffrey T. S.|name-list-style=vanc|title=Manual of Dermatologic Therapeutics|date=2007|publisher=Lippincott Williams & Wilkins|isbn=978-0-7817-6058-4|page=215|url=https://books.google.com/books?id=CP27h0r-FjwC&pg=PA215|language=en|access-date=20 September 2020|archive-date=14 January 2023|archive-url=https://web.archive.org/web/20230114072153/https://books.google.com/books?id=CP27h0r-FjwC&pg=PA215|url-status=live}}</ref>

A home treatment that may help the discomfort is using cool and wet cloths on the sunburned areas.<ref name=Sch2008/> Applying soothing lotions that contain [[aloe vera]] to sunburned areas was supported by multiple studies.<ref>{{cite journal | vauthors = Maenthaisong R, Chaiyakunapruk N, Niruntraporn S, Kongkaew C | title = The efficacy of aloe vera used for burn wound healing: a systematic review | journal = Burns | volume = 33 | issue = 6 | pages = 713–8 | date = September 2007 | pmid = 17499928 | doi = 10.1016/j.burns.2006.10.384 }}</ref><ref>{{Cite journal |pmc = 6017010|year = 2018|last1 = Luo|first1 = X.|title = Aloin Suppresses Lipopolysaccharide-Induced Inflammatory Response and Apoptosis by Inhibiting the Activation of NF-κB|journal = Molecules (Basel, Switzerland)|volume = 23|issue = 3|pages = 517|last2 = Zhang|first2 = H.|last3 = Wei|first3 = X.|last4 = Shi|first4 = M.|last5 = Fan|first5 = P.|last6 = Xie|first6 = W.|last7 = Zhang|first7 = Y.|last8 = Xu|first8 = N.|pmid = 29495390|doi = 10.3390/molecules23030517|doi-access = free}}</ref> However, others have found aloe vera to have no effect.<ref name=Sch2008>{{cite book|last1=Schwellnus|first1=Martin P.|name-list-style=vanc|title=The Olympic textbook of medicine in sport|date=2008|publisher=Wiley-Blackwell|location=Oxford, UK|isbn=978-1-4443-0064-2|page=337|url=https://books.google.com/books?id=xqqtsDmtnUQC&pg=PA337|access-date=20 September 2020|archive-date=14 January 2023|archive-url=https://web.archive.org/web/20230114072154/https://books.google.com/books?id=xqqtsDmtnUQC&pg=PA337|url-status=live}}</ref> Note that aloe vera cannot protect people from new or further sunburn.<ref name="Feily2009">{{cite journal | vauthors = Feily A, Namazi MR | title = Aloe vera in dermatology: a brief review | journal = Giornale Italiano di Dermatologia e Venereologia | volume = 144 | issue = 1 | pages = 85–91 | date = February 2009 | pmid = 19218914 }}</ref> Another home treatment is using a [[moisturizer]] that contains [[soy]].<ref name=AAD/> Furthermore, sunburn draws fluid to the skin's surface and away from the rest of the body. Drinking extra water is recommended to help prevent [[dehydration]].<ref name="AAD" />

== See also ==
* [[Sun tanning]]
* [[Freckles]]
* [[Skin cancer]]
* [[Snow blindness]]
* [[Chapped lips]]

== References ==
{{Reflist}}


== External links ==
*''Haywood R, Wardman P, Sanders R, Linge C. Sunscreens inadequately protect against ultraviolet-A-induced free radicals in skin: implications for skin aging and melanoma? J Invest Dermatol. Oct 2003;121(4):862-8.''


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[[de:Sonnenbrand]]
{{Medical resources
[[ja:&#26085;&#28988;&#12369;]]
| DiseasesDB = 13516
[[fr:Coup de soleil]]
| ICD10 = {{ICD10|L|55||l|55}}
[[nl:zonnebrand]]
| ICD9 = {{ICD9|692.71}}
| ICDO =
| OMIM =
| MedlinePlus = 003227
| eMedicineSubj =
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{{Radiation-related disorders}}
{{sunscreening agents}}
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[[Category:Dermatology]]
[[Category:Burns]]
[[Category:Sun tanning]]
[[Category:Sun tanning]]
[[Category:Hazards of outdoor recreation]]

Latest revision as of 20:07, 3 January 2025

Sunburn
A sunburnt neck
SpecialtyDermatology
ComplicationsSkin cancer
Risk factorsWorking outdoors, skin unprotected by clothes or sunscreen, skin type, age
PreventionUse of sunscreen, sun protective clothing
TreatmentAvoiding further exposure to the sun. Cool, frequent baths or showers for pain relief. Anti-inflammatory medications such as ibuprofen or aspirin can also help with pain. Drinking water to stay hydrated.

Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, usually from the Sun. Common symptoms in humans and other animals include red or reddish skin that is hot to the touch or painful, general fatigue, and mild dizziness. Other symptoms include blistering, peeling skin, swelling, itching, and nausea. Excessive UV radiation is the leading cause of (primarily) non-malignant skin tumors,[1][2] which in extreme cases can be life-threatening. Sunburn is an inflammatory response in the tissue triggered by direct DNA damage by UV radiation. When the cells' DNA is overly damaged by UV radiation, type I cell-death is triggered and the tissue is replaced.[3]

Sun protective measures like sunscreen and sun protective clothing are widely accepted to prevent sunburn and some types of skin cancer.[4] Special populations, including children, are especially susceptible to sunburn and protective measures should be used to prevent damage.[5]

Signs and symptoms

[edit]
Blisters on a sunburned shoulder

Typically, there is initial redness, followed by varying degrees of pain, the severity of which correlates with the duration and intensity of sun exposure.[citation needed]

Other symptoms can include blistering, swelling (edema), itching (pruritus), peeling skin, rash, nausea, fever, chills, and fainting (syncope). Also, heat is produced from capillaries close to the skin surface, therefore the affected area feels warm to touch. Sunburns may be classified as superficial or partial-thickness burns. Blistering is a sign of second-degree sunburn.[6]

Variations

[edit]

Minor sunburns typically cause nothing more than slight redness and tenderness to the affected areas. In more serious cases, blistering can occur. Extreme sunburns can be painful to the point of debilitation and may require hospital care.[7]

Duration

[edit]

Sunburn can occur in less than 15 minutes in response to sun exposure and in seconds when exposed to non-shielded welding arcs or other sources of intense ultraviolet light. Nevertheless, the inflicted harm is often not immediately obvious.[citation needed]

After sun exposure, the skin may turn red in as little as 30 minutes, but sunburn usually takes 2 to 6 hours. Pain is usually strongest 6 to 48 hours after exposure. The burn continues to develop for 1 to 3 days, occasionally followed by peeling skin after 3 to 8 days. Some peeling and itching may continue for several weeks.[citation needed]

Skin cancer

[edit]

Ultraviolet radiation causes sunburns and increases the risk of three types of skin cancer: melanoma, basal-cell carcinoma and squamous-cell carcinoma.[1][2][8] Of greatest concern is that the melanoma risk increases dose-dependently proportional to the number of a person's lifetime cumulative episodes of sunburn.[9] An estimated 1/3 of melanomas in the United States and Australia could be prevented with regular sunscreen use.[10]

Causes

[edit]
The cause of sunburn is the direct damage that a UVB photon can induce in DNA (left). One of the possible reactions from the excited state is the formation of a thymine-thymine cyclobutane dimer (right).

Sunburn is caused by UV radiation from the Sun but may also result from artificial sources, such as tanning lamps, welding arcs, or ultraviolet germicidal irradiation. It is the body's reaction to direct DNA damage from UVB light. This damage is mainly the formation of a thymine dimer. The damage is recognized by the body, which then triggers several defense mechanisms, including DNA repair to revert the damage, apoptosis and peeling to remove irreparably damaged skin cells, and increased melanin production to prevent future damage.[3]

Melanin readily absorbs UV wavelength light, acting as a photoprotectant. By preventing UV photons from disrupting chemical bonds, melanin inhibits both the direct alteration of DNA, as well as the generation of free radicals, to prevent them from indirectly damaging DNA. However, human melanocytes contain over 2,000 genomic sites that are highly sensitive to UV, and such sites can be up to 170-fold more sensitive to UV induction of cyclobutane pyrimidine dimers than the average site[11] These sensitive sites often occur at biologically significant locations near genes.

Sunburn causes an inflammation process that includes the production of prostanoids and bradykinin. These chemical compounds increase sensitivity to heat by reducing the threshold of heat receptor (TRPV1) activation from 109 °F (43 °C) to 85 °F (29 °C).[12] The pain may be caused by the overproduction of a protein called CXCL5, which activates nerve fibers.[13]

Skin type determines the ease of sunburn. People with lighter skin tones and limited capacity to develop a tan after UV radiation exposure have a greater risk of sunburn. Fitzpatrick's Skin phototypes classification describes the normal variations of skin responses to UV radiation. Persons with type I skin have the greatest capacity to sunburn, and type VI have the least capacity to burn. However, all skin types can develop sunburn.[14]

Fitzpatrick's skin phototypes:

  • Type 0: Albino
  • Type I: Pale white skin, burns easily, does not tan
  • Type II: White skin, burns easily, tans with difficulty
  • Type III: White skin, may burn, but eventually tans easily
  • Type IV: Light brown/olive skin, hardly burns, tans easily
  • Type V: Brown skin, usually does not burn, tans easily
  • Type VI: Black skin, very unlikely to burn, becomes darker with UV radiation exposure[15]

Age also affects how skin reacts to the sun. Children younger than six and adults older than sixty are more sensitive to sunlight.[16]

Certain genetic conditions, for example, xeroderma pigmentosum, increase a person's susceptibility to sunburn and subsequent skin cancers. These conditions involve defects in DNA repair mechanisms which decrease the ability to repair DNA damaged by UV radiation.[17]

Medications

[edit]

The risk of sunburn can be increased by pharmaceutical products that sensitize users to UV radiation. Certain antibiotics, oral contraceptives, antidepressants, acne medications, and tranquillizers have this effect.[18]

UV intensity

[edit]

The UV Index indicates the risk of sunburn at a given time and location. Contributing factors include:[16]

  1. The time of day. In most locations, the sun's rays are strongest between approximately 10 am and 4 pm daylight saving time.[19]
  2. Cloud cover. Clouds partially block UV, but even on an overcast day, a significant percentage of the sun's damaging UV radiation can pass through clouds.[20][21]
  3. Proximity to reflective surfaces, such as water, sand, concrete, snow, and ice. All of these reflect the sun's rays and can cause sunburns.
  4. The season of the year. The Sun's position in late spring and early summer can cause a more-severe sunburn.
  5. Altitude. At a higher altitude, it is easier to become burnt, because there is less of the Earth's atmosphere to block the sunlight. UV exposure increases about 4% for every 1000 ft (305 m) gain in elevation.
  6. Proximity to the equator (latitude). Between the polar and tropical regions, the closer to the equator, the more direct sunlight passes through the atmosphere over a year. For example, the southern United States gets fifty percent more sunlight than the northern United States.
Erythemal dose rate at three Northern latitudes. (Divide by 25 to obtain the UV Index.) Source: NOAA.

Because of variations in the intensity of UV radiation passing through the atmosphere, the risk of sunburn increases with proximity to the tropic latitudes, located between 23.5° north and south latitude. All else being equal (e.g., cloud cover, ozone layer, terrain, etc.), each location within the tropic or polar regions receives approximately the same amount of UV radiation over a year. In the temperate zones between 23.5° and 66.5°, UV radiation varies substantially by latitude and season. The higher the latitude, the lower the intensity of the UV rays. Sun intensity in the northern hemisphere is greatest during May, June and July—and in the southern hemisphere, November, December and January. On a minute-by-minute basis, the amount of UV radiation depends on the Sun's angle. Ultraviolet radiation is easily determined by the height ratio of any object to the size of its shadow. Height is measured parallel to the Earth's gravitational field and the projected shadow is measured on a flat, level surface. For objects wider than skulls or poles, the height and length are best measured relative to the same occluding edge. The most significant risk is at solar noon when shadows are at their minimum, and the Sun's radiation passes most directly through the atmosphere. Regardless of one's latitude (assuming no other variables), equal shadow lengths mean equal amounts of UV radiation.[citation needed]

The skin and eyes are most sensitive to damage by UV at 265–275 nm wavelength, which is in the lower UVC band that is rarely encountered except from artificial sources like welding arcs. Longer wavelengths of UV radiation cause most sunburn because those wavelengths are more prevalent in ground-level sunlight.[citation needed]

Ozone depletion

[edit]

In recent decades, the incidence and severity of sunburn have increased worldwide, partly because of chemical damage to the atmosphere's ozone layer. Between the 1970s and the 2000s, average stratospheric ozone decreased by approximately 4%, contributing an approximate 4% increase to the average UV intensity at the Earth's surface. Ozone depletion and the seasonal "ozone hole" have led to much larger changes in some locations, especially in the southern hemisphere.[22]

Tanning

[edit]

Suntans, which naturally develop in some individuals as a protective mechanism against the sun, are viewed by most in the Western world as desirable.[23] Tanning has led to an increased exposure to UV radiation from both the natural sun and tanning lamps. Suntans can provide a modest sun protection factor (SPF) of 3, meaning that tanned skin would tolerate up to three times the UV exposure as pale skin.[24]

Sunburns associated with indoor tanning can be severe.[25]

The World Health Organization, American Academy of Dermatology, and the Skin Cancer Foundation have recommended avoiding artificial UV sources such as tanning beds. Suntans are not recommended as a form of sun protection.[26][27][28]

Diagnosis

[edit]
A sunburned leg below the shorts line

Differential diagnosis

[edit]

The differential diagnosis of sunburn includes other skin pathology induced by UV radiation, including photoallergic reactions, phototoxic reactions to topical or systemic medications, and other dermatologic disorders that are aggravated by exposure to sunlight. Considerations for diagnosis include duration and intensity of UV exposure, topical or systemic medication use, history of dermatologic disease, and nutritional status.

  • Phototoxic reactions: Non-immunological response to sunlight interacting with certain drugs and chemicals in the skin which resembles an exaggerated sunburn. Common medications that may cause a phototoxic reaction include amiodarone, dacarbazine, fluoroquinolones, 5-fluorouracil, furosemide, nalidixic acid, phenothiazines, psoralens, retinoids, sulfonamides, sulfonylureas, tetracyclines, thiazides, and vinblastine.[29]
  • Photoallergic reactions: Uncommon immunological response to sunlight interacting with certain drugs and chemicals in the skin. When in an excited state by UVR, these drugs and chemicals form free radicals that react to form functional antigens and induce a Type IV hypersensitivity reaction. These drugs include 6-methylcoumarin, aminobenzoic acid and esters, chlorpromazine, promethazine, diclofenac, sulfonamides, and sulfonylureas. Unlike phototoxic reactions which resemble exaggerated sunburns, photoallergic reactions can cause intense itching and can lead to thickening of the skin.[29]
  • Phytophotodermatitis: UV radiation induces skin inflammation after contact with certain plants (including limes, celery, and meadow grass). Causes pain, redness, and blistering of the skin in the distribution of plant exposure.[14]
  • Polymorphic light eruption: Recurrent abnormal reactions to UVR present in various ways, including pink-to-red bumps, blisters, plaques and urticaria.[14]
  • Solar urticaria: A rare allergic reaction to the sun that occurs within minutes of exposure and fades within hours.[14]
  • Other skin diseases exacerbated by sunlight: Several dermatologic conditions can increase in severity with exposure to UVR. These include systemic lupus erythematosus (SLE), dermatomyositis, acne, atopic dermatitis, and rosacea.[14]

Additionally, since sunburn is a type of radiation burn,[30][31] it can initially hide a severe exposure to radioactivity. Excess radiation exposure may result in acute radiation syndrome or other radiation-induced illnesses, especially in sunny conditions. For instance, the difference between the erythema caused by sunburn and other radiation burns is not immediately obvious. Symptoms common to heat illness and the prodromic stage of acute radiation syndrome like nausea, vomiting, fever, weakness/fatigue, dizziness or seizure can add to further diagnostic confusion.[32]

Prevention

[edit]
Sunburn effect (as measured by the UV Index) is the product of the sunlight spectrum at the Earth's surface (radiation intensity) and the erythemal action spectrum (skin sensitivity). Long-wavelength UV is more prevalent, but each milliwatt at 295 nm produces almost 100 times more sunburn than at 315 nm.
Skin peeling on the upper arm as a result of sunburn – the destruction of lower layers of the epidermis causes rapid loss of the top layers
Tanning of the forearm (visible darkening of the skin) after extended sun exposure

The most effective way to prevent sunburn is to reduce the amount of UV radiation reaching the skin. The World Health Organization, American Academy of Dermatology, and Skin Cancer Foundation recommend the following measures to prevent excessive UV exposure and skin cancer:[33][34][35]

  • Limiting sun exposure between the hours of 10 am and 4 pm, when UV rays are the strongest
  • Seeking shade when UV rays are most intense
  • Wearing sun-protective clothing, including a wide-brim hat, sunglasses, and tightly woven, loose-fitting clothing
  • Using sunscreen
  • Avoiding tanning beds and artificial UV exposure

UV intensity

[edit]

The strength of sunlight is published in many locations as a UV Index. Sunlight is generally strongest when the Sun is close to the highest point in the sky. Due to time zones and daylight saving time, this is not necessarily at 12 pm, but often one to two hours later. Seeking shade using umbrellas and canopies can reduce UV exposure, but does not block all UV rays. The WHO recommends following the shadow rule: "Watch your shadow – Short shadow, seek shade!"[33]

Sunscreen

[edit]

Commercial preparations that block UV light are known as sunscreens or sunblocks. They have a sun protection factor (SPF) rating based on the sunblock's ability to suppress sunburn: The higher the SPF rating, the lower the amount of direct DNA damage. The stated protection factors are correct only if 2 mg of sunscreen is applied per square cm of exposed skin translates into about 28 mL (1 oz) to cover the whole body of an adult male. The recommended dose is much more than many people use in practice.[36] Sunscreens function as chemicals such as oxybenzone and dioxybenzone (organic sunscreens) or opaque materials such as zinc oxide or titanium oxide (inorganic sunscreens) that mainly absorb UV radiation. Chemical and mineral sunscreens vary in the wavelengths of UV radiation blocked. Broad-spectrum sunscreens contain filters that protect against UVA radiation as well as UVB. Although UVA radiation does not primarily cause sunburn, it contributes to skin aging and increases skin cancer risk.[citation needed]

Sunscreen is effective and thus recommended for preventing melanoma[37] and squamous cell carcinoma.[38] There is little evidence that it is effective in preventing basal cell carcinoma.[39] Typical use of sunscreen does not usually result in vitamin D deficiency, but extensive usage may.[40]

Recommendations

[edit]

Research has shown that the best sunscreen protection is achieved by application 15 to 30 minutes before exposure, followed by one reapplication 15 to 30 minutes after exposure begins. Further reapplication is necessary after activities such as swimming, sweating, and rubbing.[41] Recommendations are product dependent varying from 80 minutes in water to hours based on the indications and protection shown on the label. The American Academy of Dermatology recommends the following criteria in selecting a sunscreen:[42]

  • Broad spectrum: protects against both UVA and UVB rays
  • SPF 30 or higher
  • Water resistant: sunscreens are classified as water resistant based on time, either 40 minutes, 80 minutes, or not water resistant

Eyes

[edit]

The eyes are also sensitive to sun exposure at about the same UV wavelengths as skin; snow blindness is sunburn of the cornea. Wrap-around sunglasses or the use by spectacle-wearers of glasses that block UV light reduce harmful radiation. UV light has been implicated in the development of age-related macular degeneration,[43] pterygium[44] and cataracts.[45] Concentrated clusters of melanin, commonly known as freckles, are often found within the iris.

The tender skin of the eyelids can also become sunburned and can be especially irritating.[citation needed]

Lips

[edit]

The lips can become chapped (cheilitis) by sun exposure. Sunscreen on the lips does not have a pleasant taste and might be removed by saliva. Some lip balms (ChapSticks) have SPF ratings and contain sunscreens.[citation needed]

Feet

[edit]

The skin of the feet is often tender and protected, so sudden prolonged exposure to UV radiation can be particularly painful and damaging to the top of the foot. Protective measures include sunscreen, socks, or swimwear that covers the foot.

Diet

[edit]

Dietary factors influence susceptibility to sunburn, recovery from sunburn, and risk of secondary complications. Several dietary antioxidants, including essential vitamins, are effective in protecting against sunburn and skin damage associated with ultraviolet radiation, in both human and animal studies. Supplementation with Vitamin C and Vitamin E was shown in one study to reduce the amount of sunburn after a controlled amount of UV exposure.[46] A review of scientific literature through 2007 found that beta carotene (Vitamin A) supplementation had a protective effect against sunburn. The effects of beta carotene were only evident in the long-term, with studies of supplementation for periods less than ten weeks in duration failing to show any effects.[47] There is also evidence that common foods may have some protective ability against sunburn if taken for a period before exposure.[48][49]

Protecting children

[edit]

Babies and children are particularly susceptible to UV damage which increases their risk of both melanoma and non-melanoma skin cancers later in life. Children should not sunburn at any age, and protective measures can reduce their future risk of skin cancer.[50]

  • Infants 0–6 months: Children under 6mo generally have skin too sensitive for sunscreen and protective measures should focus on avoiding excessive UV exposure by using window mesh covers, wide-brim hats, loose clothing that covers the skin, and reducing UV exposure between the hours of 10am and 4pm.
  • Infants 6–12 months: Sunscreen can safely be used on infants this age. It is recommended to apply a broad-spectrum, water-resistant SPF 30+ sunscreen to exposed areas and avoid excessive UV exposure by using wide-brim hats and protective clothing.
  • Toddlers and Preschool-aged children: Apply a broad-spectrum, water-resistant SPF 30+ sunscreen to exposed areas, use wide-brim hats and sunglasses, avoid peak UV intensity hours of 10 am - 4 pm and seek shade. Sun-protective clothing with an SPF rating can also provide additional protection.

Artificial UV exposure

[edit]

The WHO recommends that artificial UV exposure, including tanning beds, should be avoided as no safe dose has been established.[51] Special protective clothing (for example, welding helmets/shields) should be worn when exposed to any artificial source of occupational UV. Such sources can produce UVC, an extremely carcinogenic wavelength of UV, which ordinarily is not present in normal sunlight, having been filtered out by the atmosphere.[citation needed]

Treatment

[edit]

The primary measure of treatment is avoiding further exposure to the sun. The best treatment for most sunburns is time; most sunburns heal completely within a few weeks.

The American Academy of Dermatology recommends the following for the treatment of sunburn:[52]

Non-steroidal anti-inflammatory drugs (NSAIDs; such as ibuprofen or naproxen), and aspirin may decrease redness and pain.[53][54] Local anesthetics such as benzocaine, however, are contraindicated.[55] Schwellnus et al. state that topical steroids (such as hydrocortisone cream) do not help with sunburns,[54] although the American Academy of Dermatology says they can be used on especially sore areas.[55] While lidocaine cream (a local anesthetic) is often used as a sunburn treatment, there is little evidence for the effectiveness of such use.[56]

A home treatment that may help the discomfort is using cool and wet cloths on the sunburned areas.[54] Applying soothing lotions that contain aloe vera to sunburned areas was supported by multiple studies.[57][58] However, others have found aloe vera to have no effect.[54] Note that aloe vera cannot protect people from new or further sunburn.[59] Another home treatment is using a moisturizer that contains soy.[55] Furthermore, sunburn draws fluid to the skin's surface and away from the rest of the body. Drinking extra water is recommended to help prevent dehydration.[55]

See also

[edit]

References

[edit]
  1. ^ a b World Health Organization, International Agency for Research on Cancer "Do sunscreens prevent skin cancer" Archived 26 November 2006 at the Wayback Machine Press release No. 132, 5 June 2000
  2. ^ a b World Health Organization, International Agency for Research on Cancer "Solar and ultraviolet radiation" Archived 29 July 2013 at the Wayback Machine IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 55, November 1997
  3. ^ a b Sunburn at eMedicine
  4. ^ Maslin, Douglas L. (November 2014). "Do suncreens protect us?". International Journal of Dermatology. 53 (11): 1319–1323. doi:10.1111/ijd.12606. PMID 25208462. S2CID 205188894.
  5. ^ Dusza, Stephen W.; Halpern, Allan C.; Satagopan, Jaya M.; Oliveria, Susan A.; Weinstock, Martin A.; Scope, Alon; Berwick, Marianne; Geller, Alan C. (February 2012). "Prospective Study of Sunburn and Sun Behavior Patterns During Adolescence". Pediatrics. 129 (2): 309–317. doi:10.1542/peds.2011-0104. ISSN 0031-4005. PMC 3269110. PMID 22271688.
  6. ^ "How to treat sunburn | American Academy of Dermatology". www.aad.org. Archived from the original on 20 March 2018. Retrieved 29 March 2018.
  7. ^ Guy, Gery P.; Berkowitz, Zahava; Watson, Meg (1 January 2017). "Estimated Cost of Sunburn-Associated Visits to US Hospital Emergency Departments". JAMA Dermatology. 153 (1): 90–92. doi:10.1001/jamadermatol.2016.4231. ISSN 2168-6068. PMC 6057474. PMID 27902809. S2CID 8254557.
  8. ^ "Facts About Sunburn and Skin Cancer" Archived 2 June 2013 at the Wayback Machine, Skin Cancer Foundation
  9. ^ Dennis LK, Vanbeek MJ, Beane Freeman LE, Smith BJ, Dawson DV, Coughlin JA (August 2008). "Sunburns and risk of cutaneous melanoma: does age matter? A comprehensive meta-analysis". Annals of Epidemiology. 18 (8): 614–27. doi:10.1016/j.annepidem.2008.04.006. PMC 2873840. PMID 18652979.
  10. ^ Olsen CM, Wilson LF, Green AC, Biswas N, Loyalka J, Whiteman DC (January 2018). "How many melanomas might be prevented if more people applied sunscreen regularly?". The British Journal of Dermatology. 178 (1): 140–147. doi:10.1111/bjd.16079. PMID 29239489. S2CID 10914195. Archived from the original on 7 August 2020. Retrieved 13 December 2019.
  11. ^ Premi, Sanjay; Han, Lynn; Mehta, Sameet; Knight, James; Zhao, Dejian; Palmatier, Meg A.; Kornacker, Karl; Brash, Douglas E. (2019). "Genomic sites hypersensitive to ultraviolet radiation". Proceedings of the National Academy of Sciences. 116 (48): 24196–24205. Bibcode:2019PNAS..11624196P. doi:10.1073/pnas.1907860116. PMC 6883822. PMID 31723047.
  12. ^ Linden DJ (2015). Touch: The Science of Hand, Heart and Mind. Viking. Archived from the original on 15 October 2021. Retrieved 1 March 2015.
  13. ^ Dawes JM, Calvo M, Perkins JR, Paterson KJ, Kiesewetter H, Hobbs C, Kaan TK, Orengo C, Bennett DL, McMahon SB (July 2011). "CXCL5 mediates UVB irradiation-induced pain". Science Translational Medicine. 3 (90): 90ra60. doi:10.1126/scitranslmed.3002193. PMC 3232447. PMID 21734176.
  14. ^ a b c d e Wolff K, Johnson R, Saavedra A (2013). Fitzpatrick's color atlas and synopsis of clinical dermatology (7th ed.). New York: McGraw-Hill Medical. ISBN 978-0-07-179302-5. OCLC 813301093.
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