Involvement of the foot in patients with psoriatic arthritis. A review of 26 cases

OBJECTIVE: To describe the clinical and radiological features of foot involvement in patients with psoriatic arthritis. METHODS: We retrospectively reviewed the medical records of patients admitted between 1972 and 1999 for psoriatic arthritis with involvement of the foot. We included all patients who had peripheral and/or axial, asymmetric, chronic inflammatory joint disease meeting or not Avila's radiological criteria for psoriatic arthritis, with or without other imaging findings suggestive of psoriatic arthritis and with or without psoriasis. RESULTS: Twenty-six patients were included. Inflammatory heel pain was reported by 14 patients, whereas forefoot involvement was found in only seven patients. Sausage toe was present in two patients. None of the patients had Bauer's toe (combining arthritis and psoriatic skin and/or nail changes) or psoriatic onychopachydermoperiostitis of the great toe. Radiological abnormalities were found in 20 patients. Half the patients had calcaneal changes. Osteoperiostitis of the great toe was noted in two patients and mushrooming in five. DISCUSSION: The features of psoriatic arthritis in Morocco seem similar to those in other countries. Hindfoot involvement was present in 53% of patients. Involvement of the forefoot was rarely recorded in the charts, suggesting missed cases because of insufficient attention to the forefoot during the physical examination and availability of anteroposterior radiographs only. Oblique views (Hirtz and Chaumet) should be obtained because they give a clearer image of the distal part of the toes, which is often difficult to analyze on anteroposterior films.