Acute rheumatic fever (ARF) is an immunologic complication of group A streptococcal pharyngitis. Rare in the West in recent decades, rheumatic fever continues to be a significant health problem in the developing world.
CASES/YEAR
30,000 (US); 1,140,000 (Global)
INCUBATION
Average of 19 days after onset of sore throat; Probable range of 10 days to 5 weeks with the same latency for initial attacks and recurrent episodes; [PPID, p. 2465]
INITIAL SYMPTOMS
Migratory polyarthritis, often with fever, occurs in about 35-66% of children; [Merck Manual, p. 2746]
PRECAUTIONS
Standard; "Not an infectious condition." [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
EPIDEMIOLOGY:
ARF is most common in 5-15 year olds; it is uncommon in ages <3 or >21. [Merck Manual, p. 2745]
CASE DEFINITION:
Major criteria are carditis, arthritis, chorea, subcutaneous nodules, and erythema marginatum (EM). Minor criteria are fever, arthralgia, heart block, and elevated acute phase reactants. [ABX Guide]
FINDINGS:
It typically presents about 2-4 weeks after streptococcal pharyngitis with painful migratory polyarthritis. If not treated with antibiotics, rheumatic fever tends to recur, causing permanent damage to heart valves. In the first episode, carditis occurs in about 50-70% of cases. The rash affects less than 6% of children and may last only 1 day. Chorea affects about 10-30% of patients, and it may cause fluctuating grip strength. Symptoms of heart failure are dyspnea, vomiting, abdominal pain, cough, and fatigue. [Merck Manual, p. 2745-6] Carditis is more common in younger children and may be asymptomatic or cause congestive heart failure. Migratory arthritis is more common in older children and affects the large joints (knees, elbows, ankles, and wrists). Chorea (abrupt, involuntary movements) occurs late in the course. Subcutaneous nodules and EM (red rings or serpiginous rash on the trunk and extremities) occur in < 10 % of cases. Valvular heart disease is the only lasting complication: 6% risk if no carditis with initial episode; 40-65% risk if murmurs or CHF at initial episode. [ABX Guide] Each attack lasts an average of 3 months in patients not treated with anti-inflammatory drugs. The rash is ever-changing, evanescent like smoke rings, and "exacerbated by a warm cloth." Individual lesions last minutes or hours, but the process may go on for weeks to months. [PPID, p. 2465-7] Patients may have hemoptysis; [Guerrant, p. 989] "The hallmark of rheumatic fever arthropathy is that it is exquisitely responsive to non-steroidal anti-inflammatory medication." Less common findings are lung infiltrates in patients with acute carditis, elevation of liver enzymes, microscopic hematuria, pyuria, and proteinuria. [Cohen, p. 473]
DIAGNOSTIC
Initial ARF: 2 Major criteria or 1 Major and 2 Minor criteria; Required criteria are evidence of preceding GAS infection (+ throat cx, increased ASO titer, or + rapid GAS Ag test); Recurrent ARF: 2 Major OR 1 Major & 2 Minor OR 3 Minor; [ABX Guide]
SIGNS & SYMPTOMS
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>arthralgia
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>fatigue, weakness
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>fever
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>fever, biphasic or relapsing
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>myalgia
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E epistaxis
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G abdominal pain
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G liver function test, abnormal
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G nausea, vomiting
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H anemia
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H leukocytosis
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N muscle weakness
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R chest pain
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R cough
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R dyspnea
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R hemoptysis
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S cellulitis or rash, circinate
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S rash (exanthem)
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S skin or subcutaneous nodule
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S skin lesion, linear or serpiginous
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U hematuria
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U pyuria
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X lung infiltrates
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*arthritis
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*endocarditis
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*myocarditis
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*pericarditis
REFERENCES FOR CASES/YEAR
1. (US) Virtual disappearance of ARF in industrialized countries in the 20th century; [Harrison ID, p. 437] Incidence of rheumatic fever is <10/100,000 in North America. [Merck Manual, p. 2745] Assuming a population of 300 million, 10 X 3000 = 30,000.
2. (Global) ARF is a disease of poverty. "It has been estimated that between 15 and 19 million people worldwide are affected by RHD, with approximately one-quarter of a million deaths occurring each year." [Harrison ID, p. 437] Estimated 33.4 million cases of rheumatic heart disease in 2015; [Cecil, p. 1875] Incidence of rheumatic fever is 19/100,00 (worldwide). [Merck Manual, p. 2745] Assuming a population of 6 billion, 19 X 60,000 = 1,140,000 cases per year.