Rheumatic Fever

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- A nonsuppurative, acute inflammatory complication from a group A streptococcal infection characterized by lesions in the connective tissues of the joints, heart, central nervous system (CNS), and subcutaneous tissues.

Causes and Incidence The causative agent of rheumatic fever (RF) is a group A streptococcus, and the disease usually is a delayed complication of an upper respiratory infection. The role of predisposing host and environmental factors is unclear. Malnutrition and overcrowding seem to be factors. However, recent outbreaks in the United States tended to be among white middle-class children and young adults. An autoimmune theory and genetic predisposition have also been hypothesized. The condition is fairly rare in developed countries, although exact numbers are difficult to determine, since many mild cases go unreported. RF is common in developing countries.

Disease Process A week to a month after a streptococcal throat infection, the streptococcal agent begins to damage the cardiac connective tissue by forming lesions that fragment the collagen fibers, infiltrate cellular lymphocytes, and leave fibrin deposits. Aschoff nodules (bullous hemorrhagic lesions) then develop, surrounded by large mononuclear and polymorphonuclear leukocytes, and the result is pericarditis, myocarditis, and left-sided endocarditis. The leaflets and chordae of the heart valves are infiltrated and thicken, resulting in stenosis and insufficiency. Joint tissue is infiltrated by lesions and Aschoff’s nodules, causing a polyarthritis that is reversible and migratory, that favors large joints, and that lasts 1 to 2 days in the affected joint before moving on. Subcutaneous nodules may form under the skin over bony prominences, and a transient nonpruritic rash (erythema marginatum) may form on the trunk and proximal regions of the extremities. The CNS may also become involved, since streptococcal antigens cause cross-reactive antibodies to bind to the nerve tissue, where damage is caused by lymphocytes. After the damage occurs, as long as 6 months may lapse before the onset of chorea, which causes involuntary, purposeless, nonrepetitive movements that subside without neurologic deficit in 3 to 6 months.

Symptoms The five major manifestations of RF (carditis, polyarthritis, subcutaneous nodules, erythema marginatum, and chorea) can appear alone or in combination, producing a number of clinical disease patterns. Signs and symptoms of each of the major manifestations are given below.

General
Low-grade fever, anorexia, malaise, pallor, weight loss, abdominal pain that mimics appendicitis

Carditis
Tachycardia, gallop rhythm, effusion, diastolic murmurs, cardiac enlargement, pericardial friction rubs, congestive heart failure, high-pitched apical murmur of mitral regurgitation, low-pitched apical middiastolic flow murmur, diastolic murmur from aortic regurgitation, mitral and aortic stenotic murmurs with chronic valvular disease

Polyarthritis
Heat, swelling, redness, and severe tenderness of major joints, with migration from joint to joint, lasting 1 to 2 days and then moving on, for about 1 month

Subcutaneous nodules
Firm, painless nodules 0.5 to 1 cm in diameter that are found in crops over bony prominences and that persist 1 to 2 weeks before resolving gradually

Erythema marginatum
Nonpruritic macular eruptions on the trunk and proximal extremities; individual lesions clear within hours, but the rash may persist for months

Chorea
Involuntary, purposeless, rapid movements of the extremities, facial grimaces, speech disturbances, muscle weakness, and emotional lability; these conditions develop up to 6 months after other symptoms and last about 2 weeks before gradually subsiding

Potential Complications Rheumatic heart disease caused by damage to mitral and aortic valves is the most common complication and may eventually lead to death. Individuals who have RF are susceptible to recurrent bouts of the disorder.

Diagnostic Tests The diagnosis is made using the guidelines of the American Heart Association; these include evidence of a previous streptococcal A infection, plus the presence of two of the five major manifestations or one major and two general manifestations, plus a positive C-reactive protein serum test or an elevated erythrocyte sedimentation rate.

Treatments

Surgery
None.

Drugs
Antiinfective drugs specific for group A streptococci during RF and afterward for prophylaxis; antipyretics for fever; nonsteroidal antiinflammatory agents for polyarthritis; corticosteroids for carditis; diuretics and digitalis for signs of congestive failure; sedation for chorea.

General
Bed rest, then limited activity for carditis; nonstimulating environment for chorea; oxygen and restriction of sodium for cardiac failure; information about the recurrent nature of RF and the importance of (1) long-term prophylactic treatment and (2) notifying health care personnel (dentists, physicians, nurses) about rheumatic history before treatment for other conditions.

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