A study of musculoskeletal manifestations in 12 patients with SAPHO syndrome

Abstract

Synovium and synovial fluid findings in SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome have not been well characterized, and only a few patients have been described in the Americas. We describe clinical, pathologic, and synovial fluid findings in 12 patients with the SAPHO syndrome: hidradenitis suppurativa (7), acne fulminans or conglobata (3), acneiform folliculitis (1) and palmoplantar pustulosis (1). Routine synovial fluid studies were performed in 6 patients, and light and transmission electron microscopic studies were performed in synovium in 2 patients and in bone in 1. The most common musculoskeletal manifestations included erosive or nonerosive oligoarthritis involving metacarpal phalangeal (MCP) and metatarsal phalangeal (MTP) joints as seen in 9 patients, sclerosis of the sacroiliac joints as seen in 5 patients, and osteitis pubis as seen in 1. Three patients had signs of skeletal hyperostosis. The patients with acne fulminans and acneiform follicul