Psoriatic arthritis of the foot and ankle: analysis of joint involvement and diagnostic errors

Forty-two patients with psoriatic arthritis arthritis who were referred to a tertiary medical center from 1983 to 1987 were reviewed. The foot and/or ankle was the most common site of joint or bone involvement, (N = 36, 86%). Twenty-six of these patients demonstrated bilateral involvement. The foot and ankle was the most common site of initial arthritis (N = 23, 55%). Errors in patient diagnosis were noted and analyzed. Eight patients with foot and ankle involvement were diagnosed and treated for either gout or compression of a digital nerve. Major causes for misdiagnosis included failure to identify psoriatic skin lesions and failure to associate foot and ankle symptoms with psoriatic arthritis.