NEW YORK – Poststreptococcal reactive arthritis in a child means fewer cardiac sequelae and less need for prophylactic antibiotics, making it worth looking for when the obvious diagnosis seems to be acute rheumatic fever, according to Dr. Stanford T. Shulman, who spoke at a meeting sponsored by New York University.
"There are several reasons why it is important to differentiate poststreptococcal reactive arthritis from [acute rheumatic fever (ARF)]," explained Dr. Shulman, chief of infectious diseases at the Children’s Memorial Hospital in Chicago and the Virginia H. Rogers Professor of Pediatric Infectious Diseases at Northwestern University, Chicago. "Rheumatic fever frequently recurs and requires long-term antibiotics to prevent recurrence."
Not fulfilling the Jones criteria is one of the first clues of PSRA. The updated 1992 Jones criteria specifies that the diagnosis of ARF relies on the presence of two of the major criteria (that is, carditis, polyarthritis of large joints, chorea, erythema marginatum, and subcutaneous nodules) or one major and two minor (arthralgia, fever, elevation of the acute phase reactants C-reactive protein and erythrocyte sedimentation rate, prolonged PR interval on an echocardiogram) criteria, plus evidence of a recent group A streptococcal infection.
Heart involvement is controversial in PSRA and if it occurs, it is quite rare, said Dr. Shulman. But carditis is the common in acute rheumatic fever and accounts for its importance. Patients with ARF who have carditis characteristically have valvulitis with mitral regurgitation most commonly, followed by mitral and aortic regurgitation. Aortic regurgitation alone is rare in ARF. Patients with only pericarditis and/or myocarditis without valvulitis do not have rheumatic heart disease. After reviewing eight clinical reports representing 120 clinical cases of PSRA, Dr. Shulman concluded that it was questionable whether carditis can occur in children with PSRA, but that carditis was completely absent in several series of adults with PSRA.
There are other ways to differentiate PSRA from ARF. Symptoms of PSRA have an acute onset, usually less than 2 weeks from the time of streptococcal infection, compared with 2-3 weeks for ARF. Arthritic symptoms are brief with ARF (about 6 days). But, in PSRA, they can last for 8 weeks or longer and may be recurrent. In PSRA, the arthritis can affect any joint, large or small, and symptoms may be symmetric or asymmetric with axial involvement. In contrast, ARF arthritis is not symmetric and does not usually affect small joints or the axis. With ARF, arthritic symptoms typically migrate but are non-migratory with PSRA. Patients in either group may complain of morning stiffness.
Response to treatment is another way to distinguish the two. If a patient with poststreptococcal arthritis responds poorly or not at all to NSAIDs, then the diagnosis is much more likely to be PSRA; ARF patients respond very promptly to such treatment, says Dr. Shulman.
Both the American Heart Association and the American Academy of Pediatrics recommend that patients with acute rheumatic fever receive antistreptococcus prophylaxis until they are 21 years old. The 2009 American Heart Association Scientific Statement recommends that patients with PSRA should be observed carefully for several months for clinical evidence of carditis and should receive up to 1 year of secondary prophylaxis after the onset of symptoms and discontinue if no findings of carditis are apparent. Dr. Shulman said he gives either IM penicillin every 4 weeks or twice daily oral penicillin for 1-2 years, which should be discontinued if no evidence of valvular disease appears. If valvular disease is found, the patient is then considered to have ARF and should continue to receive long-term secondary prophylaxis.
The good news is that there has been a dramatic decrease in the number of rheumatogenic strains of group A streptococcus in circulation, says Dr. Shulman. By comparing the prevalence of rheumatogenic and nonrheumatogenic strains of group A strep in samples from 468 children with pharyngitis taken in 1961-1968 with samples from 450 children with pharyngitis taken in 2000-2004, Dr. Shulman found that in the 1960s, two-thirds of group A strep strains in circulation were rheumatogenic, while in the later sample only one-quarter were. He and his colleagues recently completed a large 13-center U.S. and Canadian study analyzing the subtypes of group A streptococcal infection more recently in circulation through the use of M protein typing.
Dr. Shulman is a member of Merck’s speakers bureau and has research support from Quidel.