A family with cases of adult onset Still's disease and psoriatic arthritis.

Adult onset Still's disease is recognized as an adult variant of the systemic form of juvenile rheumatoid arthritis, whose disease-predisposition is still debated. On the other hand, the association between HLA subtypes and several groups of seronegative arthritis including psoriatic arthritis has been well documented. This report describes a family where adult onset Still's disease in a young man and psoriatic arthritis in his father were seen. Both patients were HLA-B39-positive, which was likely playing important pathogenic roles in the latter case. Clinical and immunological aspects of HLA-B39-related inflammatory diseases are also discussed.