Sustained myoglobinuria: the presenting manifestation of dermatomyositis.

We describe two patients with sustained myoglobinuria that did not resolve with supportive treatment. After we established a diagnosis of dermatomyositis and started treatment with corticosteroids, there was rapid resolution of the myoglobinuria. Well-documented cases of inflammatory myopathy causing myoglobinuria are rare, but their prompt recognition has important therapeutic implications.