Still's disease in an adult: A link between juvenile and adult rheumatoid arthritis.

A 52-year-old man developed rheumatoid factor negative, chronic, symmetrical polyarthritis associated with high intermittent fever and morbilliform evanescent rash at the onset. A detailed investigation and follow-up for two years failed to reveal any secondary cause. The onset and course resemble Still's disease in children. The synovial membrane histology and electron microscopy were consistent with early rheumatoid arthritis. Adult onset Still's disease reported in the literature is reviewed and compared with Still's disease in children.