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Allergic rhinitis

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Allergic rhinitis
SpecialtyImmunology Edit this on Wikidata

Allergic rhinitis is an allergic inflammation of the nasal airways. It occurs when an allergen, such as pollen, dust, or animal dander (particles of shed skin and hair) is inhaled by an individual with a sensitized immune system. In such individuals, the allergen triggers the production of the antibody immunoglobulin E (IgE), which binds to mast cells and basophils containing histamine. When caused by pollens of any plants, it is called pollinosis, and, if specifically caused by grass pollens, it is known as hay fever. While symptoms resembling a cold or flu can be produced by an allergic reaction to pollen from plants and grasses, including those used to make hay, it does not cause a fever.

IgE bound to mast cells are stimulated by allergens, causing the release of inflammatory mediators such as histamine (and other chemicals).[1] This usually causes sneezing, itchy and watery eyes, swelling and inflammation of the nasal passages, and an increase in mucus production. Symptoms vary in severity between individuals. Very sensitive individuals can experience hives or other rashes. Particulate matter in polluted air, and chemicals such as chlorine and detergents, which can normally be tolerated, can greatly aggravate allergic rhinitis. The physician John Bostock first described hay fever in 1819 as a disease.

Allergies are common. Heredity and environmental exposures may contribute to a predisposition to allergies. It is roughly estimated that one in three people has an active allergy at any given time and at least three in four people develop an allergic reaction at least once in their lives. In Western countries, between 10–25% of people annually are affected by allergic rhinitis.[2]

Signs and symptoms

Illustration depicting inflammation associated with allergic rhinitis

The characteristic symptoms of allergic rhinitis are: rhinorrhea (excess nasal secretion), itching, and nasal congestion and obstruction.[3] Characteristic physical findings include conjunctival swelling and erythema, eyelid swelling, lower eyelid venous stasis (rings under the eyes known as "allergic shiners"), swollen nasal turbinates, and middle ear effusion.[4]

There can also be behavioural signs; in order to relieve the irritation or flow of mucus, patients may wipe or rub their nose with the palm of their hand in an upward motion: an action known as the "nasal salute" or the "allergic salute". This may result in a crease running across the nose, commonly referred to as the "transverse nasal crease", and can lead to permanent physical deformity if repeated enough.[5]

Sufferers might also find that cross-reactivity occurs.[6] For example, someone allergic to birch pollen may also find that he/she has an allergic reaction to the skin of apples or potatoes.[7] A clear sign of this is the occurrence of an itchy throat after eating an apple or sneezing when peeling potatoes or apples. This occurs because of similarities in the proteins of the pollen and the food.[8] There are many cross-reacting substances.

Some disorders may be associated with allergies: Comorbidities include eczema, asthma, and depression.[citation needed]

Cause

Allergic rhinitis triggered by the pollens of specific seasonal plants is commonly known as "hay fever", because it is most prevalent during haying season. However, it is possible to suffer from hay fever throughout the year. The pollen that causes hay fever varies between individuals and from region to region; in general, the tiny, hardly visible pollens of wind-pollinated plants are the predominant cause. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk. Examples of plants commonly responsible for hay fever include:

Pathophysiology

Diagnosis

Allergy testing may reveal the specific allergens to which an individual is sensitive. Skin testing is the most common method of allergy testing. This may include intradermal, scratch, patch, or other tests. Less commonly, the suspected allergen is dissolved and dropped onto the lower eyelid as a means of testing for allergies. This test should be done only by a physician, never the patient, since it can be harmful if done improperly. In some individuals not able to undergo skin testing (as determined by the doctor), the RAST blood test may be helpful in determining specific allergen sensitivity. Peripheral eosinophilia can be seen in differential leukocyte count.

Allergy testing can either show allergies that are not actually causing symptoms or miss allergies that do cause symptoms. The intradermal allergy test is more sensitive than the skin prick test but is more often positive in people that do not have symptoms to that allergen.[10]

Even if a person has negative skin-prick, intradermal and blood tests for allergies, he/she may still have allergic rhinitis, from a local allergy in the nose. This is called local allergic rhinitis.[11] Specialized testing is necessary to diagnose local allergic rhinitis.[12]

Classification

Allergic rhinitis may be seasonal or perennial. Seasonal allergic rhinitis occurs in particular during pollen seasons. It does not usually develop until after 6 years of age. Perennial allergic rhinitis occurs throughout the year. This type of allergic rhinitis is commonly seen in younger children.[13]

Allergic rhinitis may also be classified as Mild-Intermittent, Moderate-Severe intermittent, Mild-Persistent, and Moderate-Severe Persistent. Intermittent is when the symptoms occur <4 days per week or <4 consecutive weeks. Persistent is when symptoms occur >4 days/week and >4 consecutive weeks. The symptoms are considered mild with normal sleep, no impairment of daily activities, no impairment of work or school, and if symptoms are not troublesome. Severe symptoms result in sleep disturbance, impairment of daily activities, and impairment of school or work.[14]

Treatment

The goal of rhinitis treatment is to prevent or reduce the symptoms caused by the inflammation of affected tissues. Measures that are effective include avoiding the allergen.[3] Intranasal corticosteroids are the preferred treatment if medications are required, with other options used only if these are not effective.[3] Mite-proof covers, air filters, and withholding certain foods in childhood do not have evidence supporting their effectiveness.[3]

Steroids

Intranasal corticosteroids are used to control symptoms associated with sneezing, rhinorrhea, itching, and nasal congestion. It is an excellent choice for perennial rhinitis.[1] Steroid nasal sprays are effective and safe, and may be effective without oral antihistamines. They take several days to act and so must be taken continuously for several weeks, as their therapeutic effect builds up with time.

Systemic steroids such as prednisone tablets and intramuscular triamcinolone acetonide injection are effective at reducing nasal inflammation, but their use is limited by their short duration of effect and the side-effects of prolonged steroid therapy.

Other

Other measures that may be used second line include: antihistamines, decongestants, cromolyn, leukotriene receptor antagonists, and nonpharmacologic therapies such as nasal irrigation.[3]

Antihistamine drugs can be taken orally and nasally to control symptoms such as sneezing, rhinorrhea, itching, and conjunctivitis. It is best to take the medication before exposure in the case of oral antihistamines, especially for seasonal allergic rhinitis. In the case of nasal antihistamines like azelastine antihistamine nasal spray, relief is experienced within 15 minutes allowing a more immediate or 'as-needed' approach to dosage.

Ophthalmic antihistamines (such as azelastine in eye drop form and ketotifen) are used for conjunctivitis, while intranasal forms are used mainly for sneezing, rhinorrhea, and nasal pruritus.[1]

Antihistamine drugs can have undesirable side-effects, the most notable one being drowsiness in the case of oral antihistamine tablets. First-generation antihistamine drugs such as diphenhydramine cause drowsiness, but second- and third-generation antihistamines such as cetirizine and loratadine are less likely to cause drowsiness.[1]

Pseudoephedrine is also indicated for vasomotor rhinitis. It is used only when nasal congestion is present and can be used with antihistamines. In the United States, oral decongestants containing pseudoephedrine must be purchased behind the pharmacy counter by law in effort to prevent the making of methamphetamine.[1]

Topical decongestants may also be helpful in reducing symptoms such as nasal congestion, but should not be used for long periods, as stopping them after protracted use can lead to a rebound nasal congestion called rhinitis medicamentosa.

For nocturnal symptoms, intranasal corticosteroids can be combined with nightly oxymetazoline, an adrenergic alpha-agonist, or an antihistamine nasal spray without risk of rhinitis medicamentosa.[15]

Desensitization

More severe cases of allergic rhinitis not responding to medication may benefit from allergen immunotherapy (allergy shots).[3] Allergen is given in gradually increasing doses until a maintenance dose is reached. Immunotherapy suppresses the formation of IgE and raises the titre of IgE antibody. Immunotherapy has to be given for a year before significant improvement of symptoms can be noticed. It is discontinued if uninterrupted treatment for five years shows no clinical improvement.

Complementary and Alternative Treatments

Therapeutic efficacy of complementary-alternative treatments such as acupuncture and homeopathy is not supported by currently available evidence.[16][17] Some evidence shows that acupuncture is effective for rhinitis, whereas other evidence does not. The overall quality of evidence, however, is poor.[18]

Recent studies have shown that clinical hypnosis may be effective in reducing the symptoms of allergic rhinitis, and the medication requirements of patients suffering this condition. [19]

Complications

Nasal allergy may cause recurrent sinusitis because of the obstruction to the sinus ostia. It may lead to the formation of nasal polypi. Nasal allergy can result in serious otitis media and orthodontic problems. Patients of nasal allergy have four times more risk of developing asthma.

Local allergic rhinitis

Local allergic rhinitis is an allergic reaction in the nose to an allergen, without systemic allergies. So skin-prick and blood tests for allergy are negative, but there are IgE antibodies produced in the nose that react to a specific allergen. Intradermal skin testing may also be negative.[12]

The symptoms of local allergic rhinitis are the same as the symptoms of allergic rhinitis, including symptoms in the eyes. Just as with allergic rhinitis, people can have either seasonal or perennial local allergic rhinitis. The symptoms of local allergic rhinitis can be mild, moderate, or severe. Local allergic rhinitis is associated with conjunctivitis and asthma.[12]

In one study, about 25% of patients with rhinitis had local allergic rhinitis.[20] In several studies, over 40% of people having been diagnosed with nonallergic rhinitis were found to actually have local allergic rhinitis.[11]

Steroid nasal sprays and oral antihistamines have been found to be effective for local allergic rhinitis.[12] A preliminary study found that allergy shots were also effective,[21] and clinical trials of allergy shots are being done, as of Dec. 2012.[22]

References

  1. ^ a b c d e May, J.R.; Smith, P.H. (2008). "Allergic Rhinitis". In DiPiro, J.T.; Talbert, R.L.; Yee, G.C.; Matzke, G.; Wells, B.; Posey, L.M. (eds.). Pharmacotherapy: A Pathophysiologic Approach (7th ed.). New York: McGraw-Hill. pp. 1565–75. ISBN 007147899X.
  2. ^ Dykewicz MS, Hamilos DL (February 2010). "Rhinitis and sinusitis". The Journal of Allergy and Clinical Immunology. 125 (2 Suppl 2): S103–15. doi:10.1016/j.jaci.2009.12.989. PMID 20176255.
  3. ^ a b c d e f Sur DK, Scandale S (June 2010). "Treatment of allergic rhinitis". Am Fam Physician. 81 (12): 1440–6. PMID 20540482.
  4. ^ Valet RS, Fahrenholz JM (2009). "Allergic rhinitis: update on diagnosis". Consultant. 49: 610–3.
  5. ^ Pray, W. Steven (2005). Nonprescription Product Therapeutics. p. 221: Lippincott Williams & Wilkins. ISBN 0781734983.{{cite book}}: CS1 maint: location (link)
  6. ^ Czaja-Bulsa G, Bachórska J (1998). "[Food allergy in children with pollinosis in the Western sea coast region]". Pol Merkur Lekarski. 5 (30): 338–40. PMID 10101519.
  7. ^ Yamamoto T, Asakura K, Shirasaki H, Himi T, Ogasawara H, Narita S, Kataura A (2005). "[Relationship between pollen allergy and oral allergy syndrome]". Nippon Jibiinkoka Gakkai Kaiho. 108 (10): 971–9. doi:10.3950/jibiinkoka.108.971. PMID 16285612.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  8. ^ Malandain H (2003). "[Allergies associated with both food and pollen]". Allerg Immunol (Paris). 35 (7): 253–6. PMID 14626714.
  9. ^ Allergy Friendly Trees
  10. ^ "Allergy Tests".
  11. ^ a b Rondón, Carmen; Canto, Gabriela; Blanca, Miguel (2010). "Local allergic rhinitis: A new entity, characterization and further studies". Current Opinion in Allergy and Clinical Immunology. 10 (1): 1–7. doi:10.1097/ACI.0b013e328334f5fb. PMID 20010094.
  12. ^ a b c d Rondón, C; Fernandez, J; Canto, G; Blanca, M (2010). "Local allergic rhinitis: Concept, clinical manifestations, and diagnostic approach" (PDF). Journal of investigational allergology & clinical immunology. 20 (5): 364–71, quiz 2 p following 371. PMID 20945601.
  13. ^ "Rush University Medical Center". Retrieved 2008-03-05.
  14. ^ Bousquet J, Reid J, van Weel C; et al. (August 2008). "Allergic rhinitis management pocket reference 2008". Allergy. 63 (8): 990–6. doi:10.1111/j.1398-9995.2008.01642.x. PMID 18691301. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  15. ^ Baroody FM, Brown D, Gavanescu L, Detineo M, Naclerio RM (2011). "Oxymetazoline adds to the effectiveness of fluticasone furoate in the treatment of perennial allergic rhinitis". The Journal of Allergy and Clinical Immunology. 127 (4): 927–34. doi:10.1016/j.jaci.2011.01.037. PMID 21377716.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ^ Passalacqua G, Bousquet PJ, Carlsen KH, Kemp J, Lockey RF, Niggemann B, Pawankar R, Price D, Bousquet J (2006). "ARIA update: I--Systematic review of complementary and alternative medicine for rhinitis and asthma". The Journal of Allergy and Clinical Immunology. 117 (5): 1054–62. doi:10.1016/j.jaci.2005.12.1308. PMID 16675332.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ Terr A (2004). "Unproven and controversial forms of immunotherapy". Clin Allergy Immunol. 18 (1): 703–10. PMID 15042943.
  18. ^ Witt CM, Brinkhaus B (July 2010). "Efficacy, effectiveness and cost-effectiveness of acupuncture for allergic rhinitis — An overview about previous and ongoing studies". Auton Neurosci. 157 (1–2): 42–5. doi:10.1016/j.autneu.2010.06.006. PMID 20609633.
  19. ^ Nash, MR & Klyce, D (2006). "International Journal of Clinical and Experimental Hypnosis". International Journal of Clinical and Experimental Hypnosis. doi:10.1080/00207140591008841#.UgGMn5LVArV.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  20. ^ Rondón C, Campo P, Galindo L, Blanca-López N, Cassinello MS, Rodriguez-Bada JL, Torres MJ, Blanca M. (2012). "Prevalence and clinical relevance of local allergic rhinitis". Allergy. 67 (10): 1282–8. doi:10.1111/all.12002. PMID 22913574.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  21. ^ Rondón C, Blanca-López N, Aranda A, Herrera R, Rodriguez-Bada JL, Canto G, Mayorga C, Torres MJ, Campo P, Blanca M. (2011). "Local allergic rhinitis: allergen tolerance and immunologic changes after preseasonal immunotherapy with grass pollen". The Journal of Allergy and Clinical Immunology. 127 (4): 1069–71. doi:10.1016/j.jaci.2010.12.013. PMID 21277626.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  22. ^ Klimek L, von Bernus L, Pfaar O. (2012). "Local (exclusive) IgE production in the nasal mucosa : Evidence for local allergic rhinitis". HNO (in German). 61 (3): 217–23. doi:10.1007/s00106-012-2584-0. PMID 23241861.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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