In the latest article in our Clinical Problem-Solving review series, a 28-year-old woman with an unremarkable medical history presented for evaluation of fatigue and joint pain. She initially noted pain and swelling in her right foot and ankle; these symptoms then improved, but pain in both knees and hips and in her right elbow developed.
Acute rheumatic fever is a nonsuppurative complication of pharyngeal infection with group A streptococcus, with symptoms characteristically developing 2 to 3 weeks after infection.
The differential diagnosis includes a viral syndrome, postinfectious or reactive arthritis, gonococcal infection with associated arthritis, and systemic rheumatic illnesses (e.g., systemic lupus erythematosus, Lyme disease, or rheumatoid arthritis). Crystalline arthropathies can be polyarticular as well.
Acute rheumatic fever is diagnosed by obtaining evidence of a recent group A streptococcal infection and by determining whether the clinical manifestations match particular combinations of those outlined in the Jones criteria for the disease. The major criteria are migratory arthritis, carditis, chorea, erythema marginatum, and the presence of subcutaneous nodules, and the minor criteria are arthralgia, fever, elevated levels of acute-phase reactants, and a prolonged PR interval. To satisfy the requirements for diagnosis, either two major criteria or one major and two minor criteria must be met.
Morning Report Questions
Q: What is the best way to confirm evidence of recent group A streptococcus activity in order to confirm a diagnosis of acute rheumatic fever?
A: Throat culture has poor diagnostic sensitivity because the symptoms of acute rheumatic fever appear 2 to 3 weeks after the antecedent streptococcal infection, by which time throat cultures are negative in many patients. Streptococcal serologic measurements, such as titers of antistreptolysin, anti-DNase, or both, are useful adjunctive tests, with greater sensitivity for antecedent infection, particularly if both markers are assessed. These markers are specific for previous infection with group A streptococcus, but that infection may not have been recent. Because the antistreptolysin antibody response to infection peaks at 4 to 5 weeks, rising titers can confirm a recent infection. The majority of patients with a diagnosis of acute rheumatic fever do not recall an antecedent sore throat, despite serologic evidence of recent infection.
Q: What is the treatment of choice for acute rheumatic fever?
A: Penicillin remains the treatment of choice for group A streptococcus, and it should be administered orally in a 10-day course or as a single intramuscular dose of penicillin G benzathine. Aspirin or another antiinflammatory agent should be used to treat the fever and arthritis of acute rheumatic fever and should be continued until symptoms resolve. Glucocorticoids are generally not indicated; as compared with aspirin, glucocorticoids do not appear to reduce the risk of residual cardiac disease. After an initial episode of acute rheumatic fever, patients are at high risk for recurrent episodes on reexposure to group A streptococcus. Although all patients with confirmed acute rheumatic fever should receive secondary prophylaxis with intramuscular injections of penicillin G benzathine on a monthly basis or with oral penicillin twice daily for a period of years, it is not known what duration of treatment is the most effective.