Calcinosis cutis presenting years before other clinical manifestations of juvenile dermatomyositis: report of two cases.

Calcinosis cutis in dermatomyositis is dystrophic calcification appearing late in the course of the disease. Two cases are reported here of calcinosis cutis that presented years before other clinical manifestations of juvenile dermatomyositis. The first case was a 14-year-old Thai girl who had asymptomatic subcutaneous nodules that spontaneously ruptured, exuding a chalky discharge and healing with an atrophic scar 8 years before the onset of other clinical manifestations of juvenile dermatomyositis; that is, Gottron's papules, proximal muscle weakness grade IV/V with atrophy, slightly elevated serum creatinine phosphokinase level and an abnormal electromyogram compatible with myopathy. The second case was a 15-year-old Thai boy who had calcinosis cutis 3 years before the onset of other clinical manifestations of juvenile dermatomyositis, and the calcinosis cutis was so severe that it interfered with the movement of his extremities. Both cases responded well to aluminium hydroxide therapy.