It is a multisystem disorder that occurs as a sequele to pharyngitis by group A beta-haemolytic streptococcus.
It is due to autoimmune reaction due to molecular mimicry between the antigen (M protein) of streptococcus beta- haemolyticus and cardiac myosin and sarcolemal membrane protein (laminin). As a result, antibody produced against streptococcal enzyme causes ‘cross reaction’ against the endocardium, myocardium and pericardium as well as joints and skin. There is a formation of “Aschoff’s nodule” in the heart which is pathognomonic of rheumatic fever.
Rheumatic fever is usually common in children and young adults, 5–15 years of age. There is usually a history of sore throat 1–3 weeks prior to the fever.
Diagnostic Criteria of Rheumatic Fever
It is diagnosed by revised Jones’ criteria. Following an attack of streptococcus pharyngitis, there is usually a latent period of 1–3 weeks.
1. Major criteria:
–– Shifting or migrating polyarthritis involving the big joints (knee, elbow, ankle, wrist).
–– Rheumatic chorea.
–– Erythema marginatum.
–– Subcutaneous nodule.
2. Minor criteria:
–– Previous history of rheumatic fever.
–– High ESR or CRP.
–– First or second degree AV block in ECG.
In addition, supportive evidence of previous streptococcal infection, like recent streptococcal infection, history of scarlet fever, raised ASO titre (>200) or other streptococcal antibody titre (anti-DNAse or antihyaluronidase) or positive throat swab culture.
Diagnosis is made by two or more major criteria, or one major and two or more minor criteria
plus supportive evidence of streptococcal infection.
Signs of carditis:
RF can cause carditis involving all the layers of the heart (endocardium, myocardium
and pericardium), called pancarditis.
Signs of Endocarditis
• Soft heart sounds.
• Pansystolic murmur (due to Mitral Regurgitation).
• Mid-diastolic murmur (Carey Coomb’s murmur).
• Early diastolic murmur (due to Aortic Regurgitation which is due to valvulitis with nodules on the valve).
Signs of Myocarditis
• Soft heart sounds, S3 gallop.
• Features of heart failure.
Signs of Pericarditis
• Pericardial rub (patient usually complains of chest pain).
• Pericardial effusion may be present.
It is a transient, geographical type rash with pink or red-raised edges, round margin and clear centre. It is found mostly on the trunk and proximal limbs (not in face).
These are small, mobile, firm, painless, pea-shaped nodules, felt over bony prominences, tendons or joints on the extensor surface.
Sydenham’s Chorea (St. Vitus’ Dance)
It is a neurological manifestation of acute RF, which usually occurs after 3 months of an acute attack when almost all other signs have disappeared.
• Common in children and adolescents, more in females of 5–15 years of age.
• Usually associated with emotional instability, irritability, inattentiveness and confusion.
• May occur without any feature of acute RF.
• Carditis is common.
• Speech may be explosive and halting.
• ESR, ASO titre and CRP are usually normal.
• Rheumatic chorea is usually self-limiting, and recovers within a few months.
• Treatment—sedation (haloperidol) along with other treatment and prophylaxis of rheumatic
Signs of Activity in Rheumatic Fever
• Persistent fever.
• High ESR.
• Evidence of carditis.
Investigations of RF
• CBC, ESR (there is high ESR and leucocytosis).
• ASO titre—high (in adults >200, in children >300).
• Throat swab culture (to find streptococcus beta- haemolyticus).
• Chest X-ray—cardiomegaly, pulmonary oedema.
• Pericarditis and pericardial effusion.
• Rheumatic heart disease-causing valvular stenosis and regurgitation.
Treatment of Acute RF
1. Complete bed rest.
2. Oral phenoxymethylpenicillin 250 mg 6 hourly for 10 days or a single injection of benzathine penicillin 1.2 million units, deep IM in the buttock. Erythromycin may be given, if allergic to penicillin.
3. Analgesic (to relieve pain). Aspirin 60 mg/kg per day in divided dose. Higher dose may be required.
4. Other treatment—
–– If carditis or severe arthritis—prednisolone 1–2 mg/kg daily.
–– If chorea—diazepam for mild case or haloperidol in severe case.
5. Treatment of complications like cardiac failure, valvular lesion, heart block, arrhythmia, etc., if needed.
Prophylactic Treatment of Rheumatic Fever
Recurrence is common in patient who had carditis during initial episode. In children, 20% recurrence occurs within 5 years. Recurrence is uncommon after 5 years and in patient over 25 years of age.
To prevent recurrence—oral phenoxymethylpenicillin 250 mg 12 hourly or injection benzathine penicillin 1.2 million units deep IM in the buttock every 4 weeks should be given. In penicillin sensitive cases, erythromycin (250 mg 12 hourly) may be used.
Prophylactic drug should be continued up to 21 years of age or 5 years after the last attack (recurrence after 5 years is rare), whichever comes last. After this, antibiotic prophylaxis should be given for dental or surgical procedure. However, in high-risk streptococcal infection or if the attack occurs in the 5 years or patient lives in high area of prevalence, treatment may need to be extended. If there is documented recurrence or documented rheumatic valvular heart disease, life-long prophylaxis should be considered.
Important Points Regarding Rheumatic Fever:
• Skin infection with streptococci is not associated with RF.
• Streptococcal sore throat may not be present in some cases.
• More than 50% patients of RF with carditis will develop chronic valvular disease after 10–20 years. All the cardiac valves may be involved, but most commonly the mitral valve is affected (90%). Also aortic valve may be involved. Involvement of the tricuspid and pulmonary valves is rare (5%).
• In chronic rheumatic heart disease, there may not be any history of rheumatic fever in 50%–60% cases.
• Arthritis is rheumatic fever that recovers completely without any residual change (rheumatic fever licks the joints, kills the heart).