Ultrasonographic images of the hand in a case with early eosinophilic fasciitis.

Eosinophilic fasciitis (EF), a rare rheumatic disease, usually affects the limbs symmetrically and generally spares the hands and feet. Cases of unilateral hand involvement are rarely reported. Here, we report such a rare case. Ultrasonography demonstrated thickening of the overlying skin and subcutaneous tissue, peripheral deep fascia, myositis of lumbrical muscles and adductor pollicis muscle, and edema surrounding flexor digitorum tendons. It reminds us that EF should be considered in the differential diagnosis of unilateral painful hand swelling despite being uncommon. Ultrasonography can be used to aid the diagnosis and monitor therapeutic response in patients with EF.