Rheumatic fever
Reading File
Now let me search the medical library and PubMed simultaneously for rheumatic fever.
Finding Sources
Searching PubMed
"rheumatic fever" AND "diagnosis OR management"
Good results. Now let me read the most comprehensive sources - Goldman-Cecil Medicine and Firestein's Rheumatology simultaneously.
Reading File
Reading File
Excellent content. Let me read the Jones Criteria table and treatment sections.
Reading File
Reading File
Excellent. I now have comprehensive material. Let me compile the full answer.
Acute Rheumatic Fever (ARF)
Definition and Etiology
Acute rheumatic fever is an inflammatory, non-suppurative complication of pharyngeal infection with Group A Streptococcus (GAS) - Streptococcus pyogenes. It is NOT a direct infection of the heart or joints; rather, it is an autoimmune reaction triggered by molecular mimicry - similarities between streptococcal antigens and human tissue proteins cause cross-reactive antibodies and T cells to attack host tissues.
- Skin manifestations result from delayed hypersensitivity
- Carditis results from antibody binding + T-cell infiltration of the heart
- Arthritis results from immune complex deposition in joints
- Chorea results from antibody binding to basal ganglia
Epidemiology
- Most common in children 5 to 15 years of age
- Occurs equally in males and females; however, rheumatic heart disease (RHD) is more common in women
- ARF develops in ~1.6-2.5% of patients with untreated streptococcal pharyngitis
- ~50% of preceding GAS pharyngeal infections can be asymptomatic
- Rare before age 3; infrequent after age 15
Latency
Symptoms begin approximately 2-3 weeks (average 18.6 days) after GAS pharyngitis, except chorea, which typically appears 4-8 weeks after infection.
Clinical Manifestations
The classic manifestations are remembered with the Jones Criteria:
Major Criteria
| Manifestation | Frequency | Key Features |
|---|---|---|
| Fever | >90% | Often the first sign |
| Arthritis | ~75% (adults more than children) | Migratory, large-joint polyarthritis (knees 76%, ankles 50%); exquisitely tender; responds rapidly to NSAIDs; sterile synovial fluid |
| Carditis | 15-91% (depending on echo use) | Pancarditis; mitral valve most commonly affected; Carey-Coombs murmur (middiastolic); most clinically significant complication |
| Chorea (Sydenham chorea / St. Vitus dance) | ~30% | Involuntary, non-rhythmic, purposeless movements of body, limbs, face; more pronounced unilaterally; stops during sleep |
| Erythema marginatum | <10% | Pink, non-pruritic, blanching macules/papules spreading in a serpiginous pattern on trunk and proximal limbs |
| Subcutaneous nodules | <10% | 0.5-2 cm, painless, over bony prominences or extensor tendons |
Carditis - Details
- The mitral valve is affected in almost all cases of carditis
- Aortic valve involved in ~20-30% of cases
- Tricuspid involved frequently but rarely in a meaningful manner
- Classic murmurs:
- Mitral regurgitation: high-pitched, blowing, holosystolic, apical murmur
- Carey-Coombs murmur: low-pitched, apical, middiastolic flow murmur
- Aortic regurgitation: high-pitched, decrescendo diastolic murmur (aortic area)
- Heart failure in 5-10% of first ARF episodes; more frequent with recurrences
- Myocarditis without valvulitis should NOT be attributed to rheumatic fever
Diagnosis - Revised Jones Criteria (AHA 2015)
There is no definitive test. ARF is a clinical diagnosis of exclusion.
A. Definition:
- Initial ARF: 2 major OR 1 major + 2 minor criteria
- Recurrent ARF: 2 major, OR 1 major + 2 minor, OR 3 minor criteria
Plus: Evidence of preceding GAS infection (positive throat culture, rapid antigen test, or elevated/rising streptococcal antibody titers: ASO, anti-DNase B)
B. Major Criteria
| Low-Risk Populations | Moderate/High-Risk Populations | |
|---|---|---|
| Carditis | Clinical and/or subclinical echocardiographic valvulitis | Same |
| Arthritis | Polyarticular only | Monoarticular or polyarticular |
| Chorea | Yes | Yes |
| Erythema marginatum | Yes | Yes |
| Subcutaneous nodules | Yes | Yes |
C. Minor Criteria
| Low-Risk | Moderate/High-Risk | |
|---|---|---|
| Arthralgia | Polyarthralgia | Monoarthralgia |
| Fever | ≥38.5°C | ≥38.5°C |
| ESR | ≥60 mm | ≥30 mm |
| CRP | ≥3.0 mg/dL | ≥3.0 mg/dL |
| ECG | Prolonged PR interval | Same |
Low-risk = ARF incidence <2 per 100,000 school-aged children per year, or RHD prevalence ≤1 per 1000 population per year
Investigations
- Throat culture / rapid antigen test for GAS
- ASO titer, anti-DNase B - evidence of prior GAS infection
- ESR, CRP - elevated
- CBC - normochromic normocytic anemia + leukocytosis
- ECG - prolonged PR interval (first-degree AV block)
- Echocardiogram - can detect subclinical valvulitis; should be done in all suspected ARF
Treatment
1. Eradication of GAS
- Benzathine penicillin G 1.2 million units IM (single dose) - preferred
- Oral penicillin V or amoxicillin for 10 days
- Macrolide (e.g., azithromycin) if penicillin-allergic
2. Anti-inflammatory Therapy
- Arthritis: Aspirin 80-100 mg/kg/day in divided doses (max 4-8 g/day) - traditional first line; NSAIDs (naproxen 10-20 mg/kg/day BID) are effective. Continue for 1-2 weeks after symptoms resolve.
- Carditis without heart failure: Aspirin or NSAIDs; no proven benefit of corticosteroids for long-term valve outcome
- Carditis with heart failure: Corticosteroids (prednisone) in addition to standard heart failure management
3. Secondary Prophylaxis (most important long-term measure)
Benzathine penicillin G 1.2 million units IM every 4 weeks (every 3 weeks in high-risk patients)
Duration guidelines:
| Severity | Duration |
|---|---|
| ARF without carditis | 5 years or until age 21 |
| ARF with carditis, no residual valve disease | 10 years or until age 21 |
| ARF with carditis + residual RHD (mild) | 10 years or until age 40 |
| Severe valvular disease or post-valve surgery | Lifelong |
A 2024 Cochrane systematic review (PMID 39312290) confirmed the benefit of long-term antibiotic prophylaxis for preventing recurrence and progression to rheumatic heart disease.
Rheumatic Heart Disease (RHD) - The Key Complication
- Cumulative valve damage from recurrent ARF episodes leads to chronic RHD
- Mitral stenosis is the hallmark chronic lesion (fibrosis and fusion of leaflets/subvalvular apparatus over years)
- Peak prevalence of RHD: 3rd and 4th decades of life
- Most significant cause of acquired valvular heart disease in developing countries
Key Clinical Pearls
- Arthritis responds dramatically to aspirin/NSAIDs - if it doesn't, reconsider the diagnosis
- Chorea may appear as isolated manifestation weeks after the infection, when other markers (ESR, CRP, ASO) may have normalized
- PR prolongation is a minor criterion only when carditis is not already a major criterion
- Echocardiography can detect subclinical carditis missed by auscultation alone
- Secondary prophylaxis is the cornerstone of preventing RHD - even one missed dose raises recurrence risk
- Monoarthritis counts as a major criterion in high-risk populations (not in low-risk) - a 2015 AHA revision
Sources: Goldman-Cecil Medicine, International Edition (2-Vol Set); Firestein & Kelley's Textbook of Rheumatology, 2-Vol Set; Cochrane Database of Systematic Reviews, 2024 (PMID 39312290)
This is a shared conversation. Sign in to Orris to start your own chat.