SAPHO: rare or just not recognized?

The SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome describes an association between musculoskeletal disorders, in particular hyperostosis involving the bones and joints of the anterior chest wall, and various dermatologic conditions. It has been reported in Europe and Japan, but no Australian series have been published. We describe the clinical, laboratory, and radiographic features of a group of patients with the SAPHO syndrome and compare this with the literature.

We performed a retrospective review of patients seen in our department between 1990 and 1998 who met the proposed diagnostic criteria for SAPHO. Information regarding age, sex, disease duration, skeletal site(s) of disease, presence of skin disease, previous treatment, and response to treatment was collected. Laboratory tests were reviewed, as was all available radiology and bone scintigraphy.

Six women with a mean age of 40 years fulfilled the criteria for SAPHO. The skeletal manifestations were similar to those reported in the literature, with hyperostosis of the anterior chest wall being the central feature. Cervical spine and pubic bone were other sites of involvement, whereas sacroiliitis and peripheral joint synovitis were not seen. Skin disease was less frequent in our population than has been reported in other series. Nonsteroidal anti-inflammatory drugs were frequently prescribed as first-line treatment but had limited efficacy. Intravenous pamidronate was administered to two patients, resulting in complete resolution of pain in one patient and 50% reduction in pain in the other.

The SAPHO syndrome may be underrecognized as the skin manifestations in our patients were mild or absent. Although optimal treatment for these patients remains unclear, it is important to make the diagnosis of SAPHO to avoid unnecessary investigations and treatment.