Bilateral sacroiliitis following group C streptococcal sepsis.

Reactive arthritis particularly affects individuals 20 to 40 years old. The most common preceding infections are enteric and urogenital. The association of group C and group G streptococcal infections with reactive arthritis is rare. We present a case of old-onset bilateral sacroiliitis following group C streptococcal infection in an 81-year-old woman, treated successfully with a steroid taper and infliximab.