Background: Involvement of the Achilles tendon is frequent in psoriatic arthritis, but it is easily missed at clinical examination.
Objective: To seek evidence of Achilles tendon abnormalities by means of sonography in psoriatic patients and to correlate sonographic findings with clinical symptoms (tendon and soft-tissue swelling, pain, and difficulty in walking).
Methods: Fifty-nine patients with plaque-type psoriasis (Psoriasis Area and Severity Index score, 3.7-34.7) and 50 healthy, aged-matched volunteers underwent clinical and sonographic evaluation of Achilles tendons and peritendinous structures.
Results: Eighteen (30.5%) of the 59 patients had clinical symptoms of Achilles tendinitis. Thirty-five (59.3%) of the patients had sonographic abnormalities. Of these, 13 patients had clinically symptomatic abnormalities, and 11 had psoriatic arthritis. Degenerative tendinitis was the most frequent sonographic finding (76.9%) among patients with symptomatic conditions. Five patients with symptoms did not have sonographic alterations. None of the controls had clinical or sonographic changes.
Conclusions: In psoriatic patients Achilles tendon abnormalities cannot be excluded even when they are clinically absent.