SAPHO syndrome or psoriatic arthritis? A familial case study.

OBJECTIVE To discuss the relationships between SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome and the group of spondylarthropathies. METHODS Few reports of familial SAPHO have been published. We describe three children, two sisters and one brother, whose clinical and radiological presentation was in accordance with SAPHO syndrome. RESULTS Two children developed psoriasis, and one child palmoplantar pustulosis. Both sacroiliac and sternoclavicular joints were involved in these three cases. Some features in our observations are also common to psoriatic arthritis. No association was found with HLA antigens, but a history of trauma preceding the onset of symptoms was present in all three children. CONCLUSIONS We can consider that SAPHO is nosologically related to spondylarthropathies. Psoriatic arthritis could be the missing link between SAPHO and spondylarthropathies. It is likely that both genetic and environmental factors are involved.