Rheumatic fever – disease which licks the joints and bites the heart

Rheumatic fever – disease which licks the joints and bites the heart

Rheumatic fever – disease which licks the joints and bites the heart: Rheumatic fever is an immune mediated disease involving the joints, heart, skin and brain. Commonest manifestation is pain and swelling of multiple joints (polyarthritis). Rheumatic fever commonly occurs in childhood and the frequency decreases as age advances. It is extremely uncommon after the age of forty years. Rheumatic fever occurs as a result of cross reaction of antibodies to group A beta hemolytic streptococci (a type of bacteria) with host tissue, most importantly cardiac (of the heart). The cardiac manifestation is a pancarditis (pan means all and carditis means inflammation of the heart), involving pericardium (outer layer of the heart), myocardium (middle muscular layer of the heart) and endocardium (inner lining of the heart). But the predominant involvement is that of endocardium. The cardiac valves being derived from the endocardium, are the most affected structures. Among the valves, mitral valve (valve between the left atrium and left ventricle) is the most commonly involved and aortic (between the aorta and the left ventricle), tricuspid (between the right atrium and the right ventricle) and pulmonary (between pulmonary artery and the right ventricle) valves follow in that order. It is hypothesised that the valve which bears most hemodynamic stress (stress due to the force of the blood column) bears the brunt of the damage. Hence mitral valve is most affected as it bears the systolic force of the ventricle (force produced by the contraction of the heart muscle), while the pulmonary valve which bears only the pulmonary diastolic pressure (passive pressure of the blood column in the pulmonary artery) which is very low, suffers least damage.

The cardinal manifestations of rheumatic fever are polyarthritis (pain and swelling of multiple joints), carditis (inflammation of the heart), chorea (a dance like abnormal, involuntary movement), subcutaneous nodules (nodules underneath the skin) and erythema marginatum (reddish patches in the skin with a definite margin). Polyarthritis is often described as flitting (jumping from one joint to another) and fleeting (transient). Polyarthritis of rheumatic fever usually subsides spontaneously without leaving any sequelae (after effects) and is non-deforming. Hence it is mentioned that rheumatic fever only licks the joints, while it bites the heart, producing long lasting damage to the heart valves. Very rarely joint deformities can occur (Jaccoud’s arthritis). Polyarthritis, carditis, erythema marginatum and subcutaneous nodules are seen in the acute phase (initial severe phase) while chorea is a late manifestation. Rheumatic chorea is also known as Sydenham’s chorea or St. Vitus’s dance.

Recurrence of rheumatic fever can be prevented by preventing streptococcal sore throat. This can be achieved by giving long term chemoprophylaxis (prevention with drugs) with long acting penicillin (benzathine penicillin) as monthly injection or oral penicillin on a daily basis. Benzathine penicillin is more effective, possibly because of the better compliance. But the higher incidence of anaphylaxis (allergic reaction which can be fatal) with benzathine penicillin is discouraging clinicians and patients from opting for it, even though the risk benefit ratio is still better with benzathine penicillin. Aspirin is the most important medicine used to treat an acute episode of rheumatic fever to relieve the joint pain. Involvement of the heart due to carditis may need corticosteroids (derivatives of cortisol, a hormone from the adrenal glands). A course of penicillin is also given to eradicate any streptococci residing within the throat, which can cause a relapse. Persons with heart failure will need other supportive medications like digoxin and diuretics (medicines which increase the flow of urine). Adequate rest is needed in all cases.