Latent period between streptococcal infection and occurrence of RF is 2-3 weeks. (Mean 18.6 days). Latent period remains the same for the first and the subsequent attacks.

Onset may be acute or insidious. Usually acute attacks are associated with arthritis or carditis with pericardial effusion. Insidious onset RF is seen in carditis without effusion and chorea (where early behavior changes may be missed.)

Often arthralgia is missed and remembered in retrospect when the cardiac abnormality is detected.

• Arthritis :

It's the commonest mode of presentation. Characteristically, migratory polyarthritis with overlap of joint involvement is seen. Joint involvement occurs early in the attack. Each joint swelling lastsfrom few days to one week. Pain is more marked than the swelling. Legs are usually involved first and more commonly affected. Knees are the most frequently involved (75%), followed by the ankles (50%) and then by the elbows, wrists, hips and small joints of feet (12-15%). Shoulders and small joints of the hands are the least often involved (7-8%). Rarely, temporomandibular and lumbosacral joints are involved.

Arthritis is usually self-limited and stops migrating once aspirin is started.

Lesegue has stated that: - "RF licks the joints and bites the heart"

Radiologically-Only soft tissue swelling detected.

Pathology :

There is swelling of the articular and periarticular surfaces, however there is no erosion of the articular surface. Effusion into the joint may be turbid but non-purulent. Initial cellular reaction consists of polymorphs but later mononuclear cells predominate. Fibrin may be enmeshed with the exudative cells. Swelling and fibrinoid degeneration of the connective tissue occurs.

• Carditis :

Carditis occurs in 40-50% cases of initial attack. It is the most serious form of manifestation. It usually occurs within 2-3 weeks of the attack, else it may not occur at all. The severity may range from mild to severe. Severe carditis may be fatal in the acute stage. Asymptomatic carditis may be picked up when presentation is with arthritis or chorea- "Silent carditis". It consists of 50% of all types of carditis.

Cardiac symptoms consists of shortness of breath, dependent edema, right upper quadrant pain due to an engorged liver and precordial pain in cases of pericarditis. Clinically, tachycardia is out of proportion to the fever. Basal pulse rate is raised. Venous distension with congestive failure may be present. There may be precordial prominence associated with severe cardiomegaly.

Auscultatory findings are the most conclusive. First heart sound, if indistinct or muffled suggests first degree heart block. Both sounds may be indistinct if pericardial effusion is present. There is TIC-TAC rhythm. A pericardial rub (scratchy, leathery sound altered by varying pressure of stethoscope) is heard in both phases of cardiac cycle. If it varies with respiration, then it may be of pleuropericardial origin.

An apical, high pitched, blowing, holosystolic murmur, of at least grade II/VI indicates mitral valvulitis. It may be accompanied by a low pitched mid diastolic murmur (Carey Coomb's murmur) which occurs due to relative stenosis of mitral valve in relation to a dilated left ventricle and large blood flow in early diastole. There is no presystolic accentuation or opening snap. Appearance of a new murmur or changing quality of murmur indicates presence of carditis.

Pathology :

It is usually a Pancarditis. Usually a pericarditis with myocardial damage predominates in fatal cases. Myocardium is flabby, edematous or pale. Chambers are enlarged. Heart enlarges due to dilatation of chambers or hypertrophy of the heart musculature. Within the muscle there is exudative inflammatory response with lymphocytosis and plasma cells in the interstitium. The myocardial cells are damaged. Proliferative changes are seen after 2-3 weeks & consist of perivascular aggregation of large multinucleated cells arranged around an avascular fibrinoid core - Aschoffs Body . These bodies are pathognomic of rheumatic fever. Later fibrotic scarring occurs in the viscinity of the Aschoff's nodule. These persist long after the acute attack. Immunoglobulin and complement may be demonstrated in the myofibers and vessel wall.

Endocarditis is always present: Tiny translucent nodules called verrucae are seen on the edges. Valve leaflets are edematous and infiltrated with lymphocytes. Repeated fibrin deposits on the valve cusp results in fibrosis of the valvular ring causing stenosis e.g. Mitral Stenosis. Later on commissures may be fused and chordae tendinae may be retracted and fused. Valve lesions are often responsible for the presentation as cardiac failure. Calcification of valve leaflets occurs over a time.

Pericarditis is accompanied by a serofibrinous effusion, which may get calcified but does not cause constriction at any time.

• Valve involvement in RHD :

Mitral valve involvement is the commonest. Mitral regurgitation is more common than mitral stenosis (MS). MS is a late development - except in the Indian subcontinent, where it may develop acutely. Mitral regurgitation may disappear in time.

Aortic valve involvement is always permanent. Regurgitation is commoner than stenosis. Isolated AR is rare. If it is seen, one should rule out congenital bicuspid aortic valve as well as consider a healed mitral valve lesion.

Right-sided valves are rarely involved. It may cause tricuspid regurgitation.

Auscultatory findings in valvular lesions :

Aortic Regurgitation - Early diastolic murmur. It is a high pitched, blowing decrescendo murmur heard along the left sternal border in the 2nd or 3rd space.

Aortic stenosis : A diamond shaped crescendo murmur with decreased 2nd sound is heard. Thrill is usually palpable. It does not occur in acute attack.

Presence in acute state indicates previous episodes.

Mitral stenosis : It may occur early in Indian patients. A mid diastolic rumbling murmur preceded by an opening snap is heard. Presystolic accentuation is heard because of "Atrial Kick"(increased blood flow occurs during atrial contraction.)

Mitral regurgitation : It is the commonest lesion. A high pitched, blowing Grade 3/6 murmur is heard at the apex and is conducted to the axilla.

Combination of lesions is usually seen.

• Chorea: Sydenham's Chorea or St vitus' dance :

It is abrupt, purposeless, unilateral or bilateral involuntary movement, which disappears during sleep. Hemichorea is possible. There is male to female ratio of 1:2. It does not occur in adults. It has a long latent period. All voluntary muscles may be involved. It can be suppressed voluntarily for a short time. Face and hands are involved maximally. Handwriting is affected and it may be evaluated daily for objective assessment. Speech is slurred. Inappropriate behavior like crying, laughing and in severe cases, transient psychosis "Chorea insaniens" is seen. There is no sensory or pyramidal tract involvement. There is diffuse hypotonia.

Choreic movement can be brought out by asking the patient to perform 2 or 3 motor functions one after another:

Milking sign, spooning or dishing of hands, pronator sign and jack in the box sign are positive.

Pathology :

Arteritis, cellular degeneration, embolization and infarction of cortex, basal ganglia, substantia nigra and cerebellum occur.

• Subcutaneous nodules :

They occur after first few weeks of illness. They are firm and painless- few mm to 1-2 cm in size, without signs of skin inflammation. They usually accompany carditis. They are better felt than seen. They are rare in adults.

Pathology :

It consists of fibrinoid material in strands with clear space in between. There is much edema with very few cells- fibroblast or histocytes and occasional lymphocytes. There is no fibrosis.

• Erythema marginatum :

It is early manifestation of RF, which may reappear at later stages. It is seen on trunk and proximal limbs, the face is spared. It is a non-pruritic, transient rash, 1-3 cm in size with a slightly raised periphery and clear central skin. It expands centrifugally.

• Fever - It is present with arthritis and carditis, never with isolated chorea.
  
  
• Pain in abdomen - with or without CCF
  
  
• Anorexia, nausea, vomiting
  
  
• Epistaxis
  
  
• Fatigue
  
  
• Erythema nodosum, pleurisy, Rheumatic pneumonia