A 63-year-old woman who was a nonsmoker was referred to our department with a 2-year history of recurrent seronegative rheumatoid arthritis. Each episode had resolved within 1 to 2 weeks after prednisone therapy (20 mg/day). Physical examination revealed painful and inflammatory joint effusion of the knees and ankles and digital clubbing of all fingers and toes (Figure 1). Further elicitation of her history revealed similar symptoms every 4 months since age 2 years. The remainder of physical examination findings were unremarkable.