A) Heliotrope discolouration of the eyelids, and malar or facial erythema and (B) scaly, red rash on the knuckles with Gottron’s papules

JDM=juvenile dermatomyositis. (A) Perivascular and perifascicular infl ammatory infi ltrates with necrotic fi bres, perifascicular atrophy and regeneration in a muscle biopsy. (B) MRI is a sensitive indicator of myositis. Infl amed 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) About 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.

Brian M Feldman, Lisa G Rider, Ann M Reed, Lauren M Pachman.Juvenile dermatomyositis and other idiopathic infl ammatory myopathies of childhood. www.thelancet.com Vol 371 June 28, 2008