Rheumatic fever (RF)

Revised Jones Criteria (AHA 2015) — Diagnosis of Rheumatic Fever

• Diagnosis = 2 major criteria OR 1 major criterion + 2 minor criteria + proof of a recent streptococcal infection (elevated ASO titer + or positive throat culture for GAS + or positive rapid antigen detection test for GAS)
• Major Criterion 1 — Carditis: Clinical carditis (new cardiac murmurs — mitral insufficiency ++ + aortic insufficiency + pericardial friction rub + signs of heart failure) OR subclinical carditis (echocardiographic abnormalities without clinical signs — valvular regurgitation on Doppler echo without audible murmur + valvular thickening) → subclinical carditis counts as a major criterion in high-prevalence populations
• Major Criterion 2 — Polyarthritis (low-risk populations) / Monoarthritis or Polyarthralgia (high-risk populations): Migratory arthritis (one joint after another, completely leaving the previous one) + large joints preferentially (knees + ankles + elbows + wrists) + very painful + spectacular response to NSAIDs («therapeutic test»)
• Major Criterion 3 — Sydenham's Chorea: Involuntary, non-rhythmic, arrhythmic movements of the limbs and face, emotional lability, muscle weakness, shaky handwriting. Can occur up to 6 months after streptococcal pharyngitis (late onset). Its presence alone is sufficient for the diagnosis of rheumatic fever, even without proven streptococcal infection or other criteria.
• Major Criterion 4 — Erythema marginatum: migrant annular rash + erythematous borders + pale center + non-pruritic + predominantly on trunk and limbs + fleeting and ephemeral + present in only 5–10 % of ARF
• Major Criterion 5 — Subcutaneous Nodules: firm + painless + mobile + nodules + on bony prominences (elbows + knees + wrists + ankles + spinous processes) + present in 5–10 % of RA + associated with severe carditis
• Minor criteria: fever (> 38.5 °C in low-risk populations + > 38 °C in high-risk populations) + ESR ≥ 60 mm/h + or CRP ≥ 30 mg/L + PR prolongation on ECG (first-degree atrioventricular block) + polyarthralgia (if arthritis is not used as a major criterion)

Rheumatic heart disease — the defining complication

• Frequency and importance présente dans 50–60 % des premier épisodes de RAA + détermine le pronostic à long terme + chaque récidive de RAA aggrave progressivement les lésions valvulaires → obligation de la prophylaxie secondaire
• Preferential valve involvement mitral valve = most frequent and earliest affected → acute mitral regurgitation (systolic murmur at apex radiating to axilla) → can progress to mitral stenosis in 10 to 20 years due to progressive fibrosis and calcification → aortic valve (affected in 20–30 % in association with the mitral) → aortic regurgitation → aortic stenosis is rarer
• Echocardiographic evaluation: Transthoracic echocardiogram = reference examination for detecting and quantifying valvular heart disease + typical abnormalities: thickening of the anterior mitral leaflet + mitral regurgitation + regurgitation jet towards the posterior wall of the left atrium (eccentric jet) + verrucous vegetations along the free edge of the valve leaflets
• Pericarditis pericardial friction rub + pleuritic chest pain + pericardial effusion on echo + generally resolves without sequelae with adequate anti-inflammatory treatment
• Myocarditis disproportionate tachycardia + radiographic cardiomegaly + heart failure + elevated troponin + LV systolic dysfunction on echo → poorer prognosis

Paraclinical assessment

• ASLO (antistreptolysin O) : High titer (> 200 IU/mL in adults + > 320 IU/mL in children) = serological evidence of recent streptococcal infection + rising titer between two measurements 2 weeks apart + ASLO can be negative if the pharyngitis episode was more than 2 months ago or in chorea forms (long delay) → anti-DNase B also useful as it becomes positive later and remains elevated longer
• NFS + VS + CRP hyperleukocytosis + marked biological inflammatory syndrome + ESR often > 60–80 mm/h
• Electrocardiogram PR prolongation (1st-degree AV block) = minor Jones criterion + sinus tachycardia
• Transthoracic echocardiogram to be performed on any patient with ARF to assess valvular involvement, search for subclinical carditis, even if the clinical examination is normal
• Chest X-ray cardiomegaly if carditis + pleural effusion if pericarditis

Treatment

• Strep eradication (acute episode treatment): Oral penicillin V 500 mg × 2/day × 10 days or amoxicillin 50 mg/kg/day × 10 days (child) or benzathine penicillin G 1.2 million IU IM single dose (if adherence is uncertain) + penicillin allergy: erythromycin or azithromycin
• Anti-inflammatories (arthritis + mild carditis): aspirin 80–100 mg/kg/day (child) or 4–8 g/day (adult) in 4–6 doses × 4–8 weeks → spectacular anti-inflammatory response in 24–48 h + resolution of polyarthritis → if no improvement in 48 h = reconsider diagnosis of ARF
• Corticosteroids (moderate to severe carditis + heart failure): prednisone 1–2 mg/kg/day (max 80 mg/day) × 2–4 weeks → gradual tapering over 4–6 weeks + switch to tapering aspirin + do not improve long-term valvular prognosis (NAPAC + CORTIRAA studies) but reduce acute inflammation and improve heart failure
• Treatment of heart failure if present: Diuretics + ACE inhibitors + digoxin if AF or systolic dysfunction + strict bed rest during the acute phase with carditis
• Sydenham's chorea valproic acid 15–20 mg/kg/day or carbamazepine if movements are very disabling + haloperidol if resistant + usual spontaneous resolution in 1 to 6 months

Secondary prophylaxis - prevention of recurrences

Consult at Clinique Omicron

Clinique Omicron's physician associates and nurse practitioners (NPs) diagnose and treat strep throat to prevent rheumatic fever as primary prevention, assess patients suspected of having rheumatic fever according to Jones criteria (ASLO + ECG + echocardiography + CBC + CRP), initiate streptococcal eradication antibiotic treatment and anti-inflammatory treatment, and provide secondary prophylaxis with monthly IM benzathine penicillin for patients who have had rheumatic fever. Consultations are available at several service points in Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.

The content of this page is provided for informational purposes only and does not replace the advice of a doctor, pediatrician, or cardiologist. Acute rheumatic fever is a pediatric medical emergency, and early management is crucial for long-term valve prognosis. Secondary prophylaxis must be rigorously maintained for the entire recommended duration to prevent relapses, which worsen valve damage.