Acute Rheumatic Fever
Acute rheumatic fever (ARF) is a non-suppurative sequela of Group A Streptococcus (GAS) pharyngitis that can affect the heart, joints, subcutaneous tissue, and central nervous system. ARF occurs primarily between 5 and 15 years of age and is rare in children under three. The estimated incidence is 1–3% in patients who receive inadequate treatment for GAS pharyngitis and it is very uncommon when appropriate treatment is given.
Clinical Presentation and Diagnosis
ARF typically presents 2–4 weeks after an acute infection with GAS, which can sometimes be asymptomatic. There is no single test for the condition and the diagnosis is based on clinical features embodied in the Jones Criteria. Evidence of a recent GAS pharyngitis and the presence of two major, or one major and two minor, features are required for diagnosis. The criteria are described in Table 23.1.
| Evidence of GAS1 | |
|---|---|
| Throat culture and rapid strep test are positive in 25% of cases | |
| Streptococcal Ab (ASLO, anti-DNase B, streptokinase, antihyaluronidase) is more sensitive | |
| Major criteria2 | |
| (J)oints (polyarthritis) | Pain, erythema and swelling of large joints that “migrates” |
| Persists for up to one week in each joint | |
| Pain is disproportional (↑↑ severe) to the physical findings | |
| (O) Carditis | Endocarditis is most common; also peri-, epi-, and myocarditis |
| Chest pain, friction rub, aortic and mitral regurgitation murmurs | |
| (N)odules (subcutaneous) | Firm, symmetric, 1–2 cm, painless nodules |
| Located over bony prominences or tendons, commonly the elbow | |
| (E)rythema marginatum | Non-pruritic, evanescent, macular serpiginous rash with raised erythematous borders |
| Central part of each lesion returns to normal as the rash spreads or resolves | |
| Typically on the trunk and inner thighs, upper arms | |
| (S)yndenham chorea | Abrupt, purposeless, involuntary movements |
| Associated with weakness and emotional lability | |
| Minor criteria3 | |
| Arthralgia | Significant pain in a single joint with minimal findings of inflammation |
| Cannot use as a minor criteria if polyarthritis used as a major | |
| Fever | |
| Prolonged P–R interval | |
| Elevated acute phase reactants: ESR, CRP, WBC | |
1 Required for all criteria.
2 Need two major alone, or one major and two minor.
3 Need two minor along with one major.
Recent advances in echocardiography (ECHO) have made the detection of subclinical carditis (valvular damage detected only on ECHO) readily available. However, the use of ECHO for the diagnosis of ARF in a patient who has no clinically audible murmur is still controversial. Auscultatory findings remain the basis for the diagnosis of carditis.
Joint involvement is both a major and minor criterion. Migratory arthritis is defined as arthritis in an affected joint that resolves before another joint is affected. Since migratory polyarthritis (major criterion) often improves dramatically with the use of NSAIDS, corticosteroids, or aspirin, only arthralgia (minor criterion) may be evident. Therefore, delay symptomatic treatment if a definite diagnosis of ARF has not been established. In patients presenting with arthritis, other etiologies must be ruled out (see pp. 700–703), especially septic arthritis.
Post-streptococcal reactive arthritis (PSRA) occurs in patients who have arthritis and evidence of a preceding GAS infection, but do not fulfill the Jones Criteria. Symptoms can occur as early as ten days after GAS infection, but can last two months (longer than ARF). Although it is a known entity, it is not clear whether it is truly separate from ARF. In contrast to ARF, the arthritis typically does not respond dramatically to aspirin or NSAIDs, and patients do not present with carditis. Nonetheless, give ARF prophylaxis for one year after diagnosis of PSRA.
The World Health Organization’s revised Jones Criteria include several exceptions to the criteria presented above for the following circumstances:
Recurrent attack of rheumatic fever (RF): requires two minor features and evidence of recent GAS infection in a patient with established rheumatic heart disease.
Rheumatic chorea or insidious onset of rheumatic carditis: evidence of GAS infection is not required.
Chronic valvular lesions of rheumatic heart disease: no other criteria are required.
ED Management
Since the diagnosis is based on the Jones Criteria, obtain a CBC, CRP, ESR, chest radiograph, ECG, throat culture, rapid Streptococcus swab, ASLO, and anti-DNAse B antibodies. The throat culture and rapid strep tests may be negative as the GAS pharyngitis can resolve, even without antibiotic treatment. When the ASLO and anti-DNAse B are performed simultaneously, however, evidence of a preceding GAS infection can be found in >90% of patients.
Once the diagnosis is certain, treat migratory polyarthritis with aspirin 50–75 mg/kg/day div tid or qid or naproxen 15–20 mg/kg/day div bid for 2–4 weeks. Arthritis in ARF is exquisitely sensitive to NSAIDS and resolves shortly after institution of therapy.
Treat mild to moderate carditis with high-dose aspirin 80–100 mg/kg/day div qid for 4–8 weeks, depending on response, then gradually discontinue. Give prednisone (2 mg/kg/day) for severe carditis and congestive heart failure, but first consult a pediatric cardiologist.
Chorea resolves spontaneously over 2–3 weeks and most patients do not need to be medicated. Treat severe symptoms with haloperidol, but consult a pediatric neurologist prior to instituting therapy.
Once the diagnosis is established, the eradication of any existing streptococcal infection or carriage is necessary (Table 23.2). Secondary prophylaxis is critical for preventing disease recurrences (Table 23.3). Carditis is the single most important prognostic factor for ARF, but only valvulitis leads to permanent damage. Therefore, patient age and the presence of valvulitis determines the length of prophylaxis.
| Antibiotic1 | Dose |
|---|---|
| Penicillin G benzathine | ≥27 kg: 1,200,000 units IM × 1 |
| < 27 kg: 600,000 units IM × 1 | |
| Penicillin VK | 250 mg tid or qid or 500 mg bid PO × 10 days |
| Amoxicillin | 50 mg/kg daily PO × 10 days |
| First-generation cephalosporin | 20 mg/kg/day PO × 10 days (dosing frequency varies) |
| Erythromycin ethylsuccinate | 40 mg/kg/day PO div bid or tid × 10 days |
1 Trimethoprim, sulfonamides, and tetracyclines are not effective for eradicating GAS infections
Follow-up
Indications for Admission
Bibliography
Arthritis
Arthritis results from synovial inflammation due to infectious and noninfectious causes (Table 23.4). In contrast, arthralgia is pain or tenderness without swelling.
| Diagnosis | Differentiating features |
|---|---|
| Infection/infection-related | |
| Acute rheumatic fever | Pain is out of proportion to physical exam findings |
| Classic migratory polyarthritis involves knees, ankles, elbows, and wrists | |
| Gonococcal arthritis | Subacute onset |
| Initially, pauciarticular and often migratory; can be monoarticular | |
| Adolescents may have tenosynovitis and papular or vesiculopustular rash | |
| Lyme disease | Acute onset of swelling and tenderness without warmth or erythema, most often involving the knee |
| Can be extremely painful | |
| Mostly monoarticular, sometimes migratory, rarely polyarticular | |
| Can persist for weeks to months and recur | |
| Post-infectious | Subacute onset 2–3 weeks after an illness (URI or gastroenteritis) Duration <6 weeks |
| Mono or asymmetric oligoarthritis commonly in knees and ankles | |
| Moderate pain, minimal swelling, no erythema, low-grade or no fever | |
| Septic arthritis | Most common at 1–3 years of age in one large joint (knee, hip) |
| Abrupt onset of painful, persistent and progressive arthritis | |
| Erythema, warmth, swelling, pain, and decreased range of motion (especially infants) | |
| Absence of joint effusion on ultrasound has a high negative predictive value for septic arthritis | |
| Toxic synovitis | Occurs in as many as 3% of 2–10-year-olds |
| Good response to NSAIDS | |
| Can last for 2 weeks, but resolves without complications | |
| Inflammatory | |
| Dermatomyositis | Frequently involves the small joints of the hands |
| IBD | Acute onset of a persistent oligoarthritis involving large joints, including hips |
| JIA | Arthritis lasting >6 weeks in a child <16 years old |
| Typically less painful than swelling suggests | |
| Worse in the morning, with associated stiffness | |
| Kawasaki disease | Subacute onset polyarthritis involving the small joints of the hands and feet |
| Serum sickness | Arthralgia/arthritis of the knees, ankles, shoulders, wrists, spine, and temporomandibular joint |
| Associated with myalgias, urticaria, angioedema, and hematuria | |
| SLE | Subacute onset of symmetric polyarthritis involving peripheral joints of the hands or feet |
| Large joints may be involved during disease exacerbation | |
| Despite severe pain, arthritis is nondestructive and may be persistent or intermittent | |
| Malignancy | |
| Leukemia/ | Gradual onset of a persistent mono-, poly-, or migratory arthritis |
| bone tumors | Pain out of proportion to physical findings and may be worse at night, can awaken child from sleep |
| Can be associated with fever, weight loss, and anemia | |
| Non-inflammatory | |
| Benign growing | Pain is mild, generally localized to long bones |
| pains | Pain can wake child from sleep but easily resolved with massage and reassurance |
| RSD | Pain severely out of proportion with examination |
| Affected joint/limb in preferred position of comfort | |
| Often the affected limb is cool to touch. | |
| Trauma/overuse | |
| Fracture | Point tenderness, can be associated with some peri-articular swelling |
| Hypermobility | No objective arthritis, usually only arthralgias |
| Can affect upper and/or lower extremities | |
| Traumatic arthritis | Acute or chronic onset of intermittent pain that is worse with activity |
| Typically one joint is involved (elbow, shoulder, knee, hip) | |
| May have an associated fracture, ligamentous injury, bursitis, or tenovitis | |
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