Streptococcal toxic shock syndrome due to Streptococcus dysgalactiae subsp. equisimilis from retroperitoneal panniculitis during the treatment with anti-IL-6 receptor antibody: A case report.

A 53-year-old man with adult-onset Still's disease developed severe streptococcal toxic shock syndrome (STSS) due to Streptococcus dysgalactiae subsp. equisimilis (SDSE), following retroperitoneal panniculitis. He was receiving tocilizumab (TCZ), an interleukin-6 receptor inhibitor.