Poststreptococcal reactive arthritis.

Five cases (three children and two young women) of sterile inflammatory arthritis are described, each preceded by a streptococcal infection. A throat swab from one patient grew group A, beta haemolytic streptococci, and in each case unequivocal evidence of seroreaction to streptococcal antigens was present. The long term outcome in all cases was excellent, though one patient (female, 24 years of age) required prophylactic penicillin for three months. The diagnosis of a definite recent streptococcal infection is sometimes difficult as throat swabs may be negative and the diagnostic serological reaction missed unless antibodies to multiple antigens (particularly antistreptolysin O and DNAase B) are tested. These cases may represent a reactive arthritis and should be distinguished from rheumatic fever, streptococcal septic arthritis, viral arthritides, acute rheumatic diseases such as juvenile chronic arthritis, and a monoarticular presentation of a seronegative spondyloarthropathy.