Focal myopathy induced by chronic heroin injection is reversible.

We report a patient who developed a focal myopathy with prominent contractures of his thigh muscles induced by chronic heroin injection. Muscle biopsy and magnetic resonance imaging (MRI) were indicative of a fibrotic and inflammatory process. Treatment with steroids, D-penicillamine, and physical therapy led to full functional recovery within 6 months. Sequential electromyographic (EMG) studies and muscle biopsies showed evidence of regenerating muscle fibers and absence of inflammatory cells. We conclude that heroin-induced focal myopathy is reversible and that combination therapy with D-penicillamine and steroids may be useful.