SAPHO: syndrome or concept? Imaging findings

The SAPHO syndrome was a term coined to include a variety of musculoskeletal disorders associated with skin conditions, mainly palmoplantar pustulosis and acne conglobata. It is more correctly a spectrum which includes the following: skin lesions, osteoarticular manifestations of synovitis hyperostosis and osteitis affecting particular target sites, and-a clinical course marked by relapses and remissions. The major sites of involvement are the anterior chest wall, the spine, long bones, flat bones, and large and small joints. The distribution and severity of involvement varies from the adult to the pediatric form of chronic recurrent multifocal osteomyelitis (CRMO). The diagnosis of SAPHO syndrome is not difficult when the typical osteoarticular lesions are located in characteristic target sites. The diagnosis is more difficult if atypical sites are involved and there is no skin disease.