RHEUMATIC DISEASE

Rheumatic fever is an acute immunologically mediated multisystem inflammatory disease that occurs few weeks after an attack of group A beta- hemolytic streptococcal pharyngitis. It is not an infective disease.

The most commonly affected age group is children between the ages of 5-15 yearsQ.

The disease is a type II hypersensitivity reaction in which antibodies against ‘M’ protein of some streptococcal strains (1, 3, 5, 6, and 18) cross-react with the glycoprotein antigens in the heart, joints and other tissues (molecular mimicry).

CLINICAL FEATURES It presents with fever, anorexia, lethargy and joint pain 2-3 WEEKS after an episode of Streptococcal Infection is required for diagnosis

Migratory Polyarthritis is the commonest major manifestation. Q

Salient feature`s of the major criteria

Carditis All the layers of the heart namely , myocardium and endocardium are involved, so this is called pancarditis. The pericarditis is associated with fibrinous/serofibrinous and is called as ‘bread and butter’ pericarditis. It may manifest as breathlessness (due to heart failure or ), or (usually due to pericarditis or pancarditis). Other features include , cardiac enlargement and new or changed murmurs. A soft mid-diastolic murmur (the ) is typically due to valvulitis, with nodules forming on the leaflets. Aortic regurgitation occurs in 50% of cases but the tricuspid and pulmonary valves are rarely involved. Pericarditis may cause chest pain, a and precordial tenderness. Cardiac failure may be due to myocardial dysfunction or valvular regurgitation.

Valvular involvement is common in rheumatic heart disease. The most common valve to be affected is the mitral valve and least commonly affected is pulmonary valve.

V Imp. In acute rheumatic heart disease, the most common valvular lesion is mitral regurgitation and in chronic rheumatic heart disease, it is mitral stenosis.

Migratory polyarthritis There is involvement of the large joints of the body. An acute painful asymmetric and migratory of the large joints typically affects the knees, ankles, elbows and wrists . It is more commonly seen in the adults as compared to children. The arthritis involves one joint after the other (migratory) and subsides spontaneously without any residual deformability in the joints (non-erosive arthritis). Clinically, this is the most commonly seen manifestation and the joint pain shows dramatic response to salicylates like aspirin.

Subcutaneous nodules These are painless subcutaneous lesions found on the extensor surface of the elbows, shin and the occiput.

Erythema marginatum There is presence of red macular rash more easily appreciated in fair skinned individuals sparing the face and without residual scarring.

Sydenham’s chorea It is a late manifestation of the disease characterized by presence of involuntary, purposeless movements associated with emotional lability of the patient

PATHOLOGY

Microscopically, the characteristic feature of rheumatic heart disease is Aschoff’s body. The latter consist of foci of swollen eosinophilic surrounded by T-lymphocytes, few plasma cells and plump called Anitschkow cells ( for RF) Q. These distinctive cells have abundant cytoplasm and central round-to-ovoid nuclei in which the chromatin is disposed in a central, slender, wavy ribbon (hence, they are also called as “caterpillar cells”).

The myocardium has Aschoff’s bodies in the perivascular location. The involvement of the endocardium results in fibrinoid within the cusps or along the tendinous cords which also have small vegetations called verrucae present along the lines of closure. The presence of mitral regurgitation also induces irregular thickening in the left atrial wall called as MacCallum plaques.

Chronic RHD is characterized by organization of the acute inflammation and subsequent fibrosis. The valves show leaflet thickening, commissural fusion and shortening, and thickening and fusion of the tendinous cords. There is mitral stenosis called as ‘fish- mouth’ or ‘button-hole’ stenosis. Mitral stenosis may also lead to atrial fibrillation and thromboembolic phenomenon in these patients.

INVESTIGATION

Evidence of a systemic illness (non-specific) •CBC for Leucocytosis, - ESR and CRP

Evidence of preceding streptococcal infection (specific) • Throat swab culture: group A β-haemolytic streptococci (also from family members and contacts) • Antistreptolysin O antibodies (ASO titres): rising titres, or levels of > 200 U (adults) or > 300 U (children)

Evidence of • Chest X-ray: cardiomegaly; pulmonary congestion • ECG: first- and rarely second-degree AV block; features of pericarditis; T-wave inversion; reduction in QRS voltages • Echocardiography: cardiac dilatation and valve abnormalities

Management of the acute attack A single dose of benzyl penicillin (1.2 million U IM) or oral phenoxymethylpenicillin (250 mg 4 times daily for 10 days) should be given on diagnosis to eliminate any residual streptococcal infection. If the patient is penicillin-allergic, erythromycin or a cephalosporin can be used. Treatment is then directed towards limiting cardiac damage and relieving symptoms.

Bed rest and supportive therapy Bed rest is important, as it lessens joint pain and reduces cardiac workload. The duration should be guided by symptoms, along with temperature, leucocyte count and ESR, and should be continued until these have settled

Aspirin This usually relieves the symptoms of arthritis rapidly and a response within 24 hours helps confirm the diagnosis. A reasonable starting dose is 60 mg/kg body weight/day, divided into six doses. In adults, 100 mg/kg per day may be needed up to the limits of tolerance or a maximum of 8 g per day. Mild toxicity includes nausea, tinnitus and deafness; vomiting, tachypnoea and acidosis are more serious. Aspirin should be continued until the ESR has fallen, and then gradually tailed off.

Corticosteroids These produce more rapid symptomatic relief than aspirin and are indicated in cases with carditis or severe arthritis. There is no evidence that long-term steroids are beneficial. Prednisolone (1.0–2.0 mg/kg per day in divided doses) should be continued until the ESR is normal, and then tailed off.

PROPHYLAXIS prophylaxis with penicillin should be given as benzathine penicillin (1.2 million U IM monthly), ifcompliance is in doubt, or oral phenoxymethylpenicillin (250 mg twice daily). Sulfadiazine or erythromycin may be used if the patient is allergic to penicillin; sulphonamides prevent infection but are not effective in the eradication of group A streptococci. Further attacks of are unusual after the age of 21, when treatment may be stopped. However, it should be extended if an attack has occurred in the last 5 years, or if the patient lives in an area of high prevalence or has an occupation (e.g. teaching) with high exposure to streptococcal infection. In those with residual heart disease, prophylaxis should continue until 10 years after the last episode or 40 years of age, whichever is later. Long-term antibiotic prophylaxis prevents another attack of acute rheumatic fever but does not protect against infective .