Features of juvenile dermatomyositis

(A) Perivascular and perifascicular inflammatory infiltrates with necrotic fibres, perifascicular atrophy, and regeneration in a muscle biopsy.
(B) Magnetic resonance imaging (MRI) is a sensitive indicator of myositis. Inflamed areas appear bright on short-tau inversion recovery-weighted images (arrows).
(C) Capillaries are most often abnormal when viewed at the nailfold. Typical changes of dilatation with adjacent drop out (arrow) is seen.
(D) Approximately 30% of JDM patients have dystrophic calcinosis.
(E) Cutaneous ulceration with central necrosis, crust, and surrounding erythema at the elbow of a 10-year-old boy with severe JDM.
(F) Lipoatrophy of the forearm (arrow) in a boy with JDM.