Rheumatic Fever and Rheumatic Heart Disease

A systemic inflammatory disease of childhood, acute rheumatic fever develops after infection of the upper respiratory tract with group A beta-hemolytic streptococci. Rheumatic fever principally involves the heart, joints, central nervous system, skin, and subcutaneous tissue. It commonly recurs.

The term rheumatic heart disease refers to cardiac involvement in rheumatic fever—its most destructive effect. Cardiac involvement develops in up to 50% of patients with rheumatic fever and may affect the endocardium, myocardium, or pericardium during the early acute phase. It may later affect the heart valves, causing chronic valvular disease.

The extent of damage to the heart depends on where the disorder strikes. Pericarditis causes a pericardial friction rub and, occasionally, pain and effusion. Myocarditis produces characteristic lesions called Aschoff bodies in the acute stages as well as cellular swelling and fragmentation of interstitial collagen, leading to formation of a progressively fibrotic nodule and interstitial scars. Endocarditis causes valve leaflet swelling, erosion along the lines of leaflet closure, and blood, platelet, and fibrin deposits, which form beadlike vegetation. It usually affects the mitral valve in females and the aortic valve in males; in both, it affects the tricuspid valves occasionally and the pulmonic valve rarely.

Long-term antibiotic therapy can minimize the recurrence of rheumatic fever, reducing the risks of permanent cardiac damage and valvular deformity. Although rheumatic fever tends to be familial, this tendency may reflect contributing environmental factors. For example, in lower socioeconomic groups, the incidence is highest in children between ages 5 and 15, likely due to malnutrition and crowded living conditions. Rheumatic fever usually strikes during cool, damp weather in winter and early spring. In the United States, it’s most common in the northern states.

Causes

Rheumatic fever appears to be a hypersensitivity reaction in which antibodies produced to combat streptococci react and produce characteristic lesions at specific tissue sites. How and why group A streptococcal infection initiates the process are unknown. Because few people infected with Streptococcus infection ever contract rheumatic fever (about 0.3%), altered host resistance is probably involved in its development or recurrence.

Complications

The long-term effects of rheumatic fever usually destroy the mitral and aortic valves, leading to severe pancarditis and occasionally producing pericardial effusion and fatal heart failure. Of the patients who survive these complications, about 20% die within 10 years.

Assessment Findings

Nearly all affected patients report having had a streptococcal infection a few days to 6 weeks earlier. They usually have a recent history of fever that spikes to at least 100.4° F (38° C) late in the afternoon, sudden-onset sore throat, pain on swallowing, headache, and abdominal pain; nausea and vomiting may also occur, especially in children. Most patients complain of migratory joint pain in the knees, ankles, elbows, and hips (poly-arthritis). Swelling, redness, and signs of effusion typically accompany this pain.

If pericarditis is involved, the patient may complain of sharp, sudden pain that usually starts over the sternum and radiates to the neck, shoulders, back, and arms. The pain is usually pleuritic, increases with deep inspiration, and decreases when the patient sits up and leans forward. (This position pulls the heart away from the diaphragmatic pleurae of the lungs.) The pain may mimic that of a myocardial infarction.

A patient with heart failure caused by severe rheumatic carditis may complain of dyspnea, right upper quadrant pain, and a hacking, nonproductive cough. Inspection may reveal skin lesions, such as erythema marginatum, which is a nonpruritic, macular, and transient rash. The lesions are red with blanched centers and well-demarcated borders and typically appear on the trunk and extremities.

Subcutaneous nodules near tendons or the bony prominences of joints may be noted; these nodules are firm, movable, nontender, and about 1/8″ to 3/4″ (0.3 to 2 cm) in diameter. They occur around the elbows, knuckles, wrists, and knees and, less commonly, on the scalp and backs of the hands. These nodules persist for a few days to several weeks and, like erythema marginatum, commonly accompany carditis.

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