No Enthesis Should Be Overlooked When Psoriatic Arthritis Is Suspected: Enthesitis of the Extensor Digitorum Tendons

A common and well-documented feature of spondyloarthropathies is inflammation of the peripheral enthesis1. Ultrasound (US) imaging is useful when assessing enthesitis, and many investigators have described its features2,3. A 50-year-old man with psoriasis developed morning stiffness, tenderness, and swelling of small joints in the hands asymmetrically during the last month. Clinical examination revealed tenderness and swelling of the proximal interphalangeal joints (PIP) of the second, third, and fourth fingers …