Rheumatic fever

Rheumatic fever
Specialty	Cardiology

Rheumatic fever is an inflammatory disease which may develop after a Group A streptococcal infection (such as strep throat or scarlet fever) and can involve the heart, joints, skin, and brain.

General information

Rheumatic fever is common worldwide and is responsible for many cases of damaged heart valves. In the Western countries, it became fairly rare since the 1950s, possibly due to higher hygienic standards. While it is far less common in the United States since the beginning of the 20th century, there have been a few outbreaks since the 1980s. Although the disease seldom occurs, it is serious and has a mortality of 2–5%.

Rheumatic fever primarily affects children between ages six and 15 and occurs approximately 20 days after strep throat or scarlet fever. In up to a third of cases, the underlying strep infection may not have caused any symptoms.

The rate of development of rheumatic fever in individuals with untreated strep infection is estimated to be 3%. The rate of development is far lower in individuals who have received antibiotic treatment. Persons who have suffered a case of rheumatic fever have a tendency to develop flare-ups with repeated strep infections.

The recurrence of rheumatic fever is relatively common in the absence of maintenance of low dose antibiotics, especially during the first three to five years after the first episode of rheumatic fever. Heart complications may be long-term and severe, particularly if the heart valves are involved.

Diagnosis: modified Jones criteria

T. Duckett Jones, MD, first published these criteria in 1944. They have been periodically revised by the American Heart Association in collaboration with other groups. Two major criteria, or one major and two minor criteria, when there is also evidence of a previous strep infection support the diagnosis of rheumatic fever. [1][2]

Major criteria

• Carditis: inflammation of the heart muscle which can manifest as congestive heart failure with shortness of breath, pericarditis with a rub, or a new heart murmur.
• Migratory polyarthritis: a temporary migrating inflammation of the large joints, usually starting in the legs and migrating upwards.
• Sydenham's chorea (St. Vitus' dance): a characteristic series of rapid movements without purpose of the face and arms. This can occur very late in the disease.
• Erythema marginatum: a long lasting rash that begins on the trunk or arms as macules and spread outward to form a snakelike ring while clearing in the middle. This rash never starts on the face and is made worse with heat.
• Subcutaneous nodules (a form of Aschoff bodies): painless, firm collections of collagen fibers on the back of the wrist, the outside elbow, and the front of the knees. These now occur infrequently.

Minor criteria

• Fever: temperature elevation
• Arthralgia: Joint pain without swelling
• Laboratory abnormalities: increased Erythrocyte sedimentation rate, increased C reactive protein, leukocytosis
• Electrocardiogram abnormalities: a prolonged PR interval
• Evidence of Group A Strep infection: positive culture for Group A Strep, elevated or rising Antistreptolysin O titre
• Previous rheumatic fever or inactive heart disease

Other signs and symptoms

• Abdominal pain
• Nosebleeds

Rheumatic fever is common worldwide and is responsible for many cases of damaged heart valves. While it is far less common in the U.S. since the beginning of the 20th century, there have been a few outbreaks since the 1980s.

Rheumatic fever primarily affects children between ages 6 and 15 and occurs approximately 20 days after strep throat or scarlet fever. In up to a third of cases, the underlying strep infection may not have caused any symptoms.

The rate of development of rheumatic fever in individuals with untreated strep infection is estimated to be 3%. Persons who have suffered a case of rheumatic fever have a tendency to develop flare-ups with repeated strep infections

Pathophysiology

Rheumatic fever is a systemic disease affecting the peri-arteriolar connective tissue which occurs after an untreated Group A streptococcal pharyngeal infection. It is believed to be caused by antibody cross-reactivity. Group A streptococcus pyogenes has a cell wall that is composed of branched polymers which sometimes contain "M proteins" that are highly antigenic. The antibodies the immune system generates against the "M proteins" may cross react with cardiac myofiber sarcolemma and smooth muscle cells of arteries, inducing cytokine release and tissue destruction. Acute rheumatic valvular lesions may also invlolve a delayed hypersensitivity reaction as these lesions predominantly contain T-helper cells and macrophages. [3]

Treatment

The management of acute rheumatic fever is geared toward the reduction of inflammation with anti-inflammatory medications such as aspirin or corticosteroids. Individuals with positive cultures for strep throat should also be treated with antibiotics. Another important cornerstone in treating rheumatic fever includes the continuous use of low dose antibiotics (such as penicillin, sulfadiazine, or erythromycin) to prevent recurrence.

Infection

Patients with positive cultures for streptococcus pyogenes should be treated with penicillin as long as allergy is not present. This treatment will not alter the course of the acute disease.

Inflammation

Patients with significant symptoms may require corticosteroids. Salicylates are useful for pain.

Heart failure

Some patients develop significant carditis which manifests as congestive heart failure. This requires the usual treatment for heart failure: diuretics, digoxin, etcetera. Unlike normal heart failure, rheumatic heart failure responds well to corticosteroids.

Prevention

Prevention of recurrence is achieved by eradicating the acute infection and prophylaxis with antibiotics. The American Heart Association recommends prophylaxis continue at least 10 years.

Nurses also have a role in prevention, primarily in screening school-aged children for sore throats that may be caused by group A streptococci.

References

• Jones TD. The diagnosis of rheumatic fever. JAMA. 1944; 126:481–484
• Ferrieri P. Proceedings of the Jones criteria workshop. Circulation 2002; 106 : 2521–23
• Acute Rheumatic Fever eMedicine
• Rheumatic Fever Emergency Medicine eMedicine
• Rheumatic Fever Pediatrics eMedicine

External links

• NIH Rheumatic Fever Guide
• Rheumatic fever information from Seattle Children's Hospital Heart Center