[SAPHO syndrome: common denominator for various bone and skin diseases]

The acronym 'SAPHO' stands for synovitis, acne, pustulosis, hyperostosis and osteitis. Three subtypes of SAPHO can be distinguished which have the following features in common: sternoclavicular hyperostosis and sterile inflammatory lesions in both bone and skin. These subtypes are: sternocostoclavicular hyperostosis, chronic recurring multifocal osteomyelitis, and pustular arthro-osteitis. Hyperostosis and osteitic lesions may be similar to those seen in malignant bone tumours. Synovitis generally does not lead to bone erosions and one-third of the patients develop sacroiliitis. The SAPHO syndrome and seronegative spondyloarthropathy share some common features (a higher prevalence of the HLA-B27 antigen, occurrence of sacroiliitis and a higher incidence of chronic inflammatory bowel disease and psoriasis). Aetiology and pathogenesis of SAPHO are unknown; prognosis is good. The SAPHO syndrome often runs a protracted course, with intermittent relapses and remissions without resulting serious disability. Treatment is aimed only at symptomatic relief and mainly consists of analgetics and nonsteroidal antiinflammatory drugs.