Psoriatic Arthritis: A Comparative Radiographic Study of Rheumatoid Arthritis and Arthritis Associated with Psoriasis

Abstract

Patients (157) with psoriasis and various rheumatic complaints have been studied. In those with osetoarthritis, gout, rheumatic fever, and muscular rheumatism, there were no unusual clinical or radiographic features and their association seemed fortuitous. Patients (121) with erosive arthritis were analyzed in the light of the Rose-Waaler differential agglutination test and compared with 91 patients with uncomplicated rheumatoid arthritis and a positive test, who were matched by age, sex, and duration of arthritis. In all patients radiographs of the hands, feet, and sacro-iliac joints were taken. Patients (18) with psoriasis and erosive arthritis had a positive differential agglutination test and were concluded to be examples of coincidental rheumatoid arthritis on clinical and radiographic grounds. Patients (103) with psoriasis, erosive arthritis, and a negative differential agglutination test were thought to be examples of psoriatic arthritis. This arthritis was less severe than rheumatoid arthritis, and was characterized by distal interphalangeal joint involvement, erosion of the terminal phalanges, and a greater incidence of sacro-iliac joint changes.