Group A streptococcal infection, occurs frequently, mainly as acute tonsillitis, might lead to a variety of immune manifestations in genetically susceptible hosts. Rheumatogenic M type serotypes lead to Rheumatic fever (RF), which is the common prototype of post-streptococcal disease, but today, post-streptococcal reactive arthritis (PSRA) as a self-contained entity is more common. Less common presentations are polyarteritis nodosa, and cutaneous PAN. Other syndromes, such as HSP, PANDAS, and juvenile arthritis flare might be related to strep. Post streptococcal glomerulonephritis is related to streptococcal skin disease. The relationship between the streptococcal infection and the disease is important in assessing the need for penicillin prophylaxis in preventing further flares.
PSRA is defined as arthritis associated with a recent Group A streptococcal infection in a patient who does not fulfill the Jones criteria for the diagnosis of RF. The disease has a bimodal age onset, occurring primarily in children, with a second peak in young adults.
Clinical presentation varies from mono- or polyarthritis, in large, small, and even axial joints and enthesitis. The course is often prolonged or with recurrent episodes lasting up to several months. Response to NSAIDs is reduced compared to that of RF.
Over or under diagnosis may occur due to misinterpretation of antistreptolysin O (ASO) serum levels, which rise 3 to 4 weeks after the infection, and can remain elevated for months. Knowing the normal values in the local healthy population is important. Pediatric ASO values are higher than adult levels.
Based on a large cohort of children with PSRA or RF, we were able to differentiate and diagnose between the two entities. Using simple variables, we found that a lower sedimentation rate and CRP at disease onset, longer time before resolution of joint symptoms after starting anti-inflammatory therapy, and higher recurrence rate of arthritis after discontinuing anti-inflammatory therapy, were typical for PSRA. This discriminating equation may be used to classify these two entities correctly.
The association of PSRA and carditis is controversial. Following previous small studies that reported late cardiac involvement in a few children with PSRA and case reports of cardiac involvement in adults, the American Heart Association currently recommends anti-streptococcal prophylaxis for one year, repeat echocardiogram, and discontinuation of prophylaxis if normal. Since this statement has a low level of evidence (Class 2B, level C) a prospective, double blind, placebo controlled study is needed to definitively assess the necessity of anti-streptococcal prophylaxis in PSRA.
Recent large adult studies did not find late carditis, despite patients not having received prophylaxis and suggest that prophylaxis in adult PSRA is not needed. In our cohort of 80 pediatric PSRA, we did not find late carditis either.
PANDAS is controversial based on clinical grounds, and in the efficacy of immune therapy. Penicillin prophylaxis has not been proven effective. The need for penicillin prophylaxis in HSP, juvenile arthritis flare, PAN or CPAN is not clear. In recurrent relapsing episodes, it is worth a try.
In summary, different approaches to antibiotic prophylaxis in the various post-strep syndromes are justified. A prospective, double blind, placebo controlled study is needed to definitively assess the necessity of anti-streptococcal prophylaxis in PSRA and in the other less common syndromes. Until then, using the art of medicine for clinical judgment, diagnosis, and treatment is suggested. If in doubt, treat as RF.
Disclosure of Interest None Declared
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