Abstract
A 48-year-old white woman presented with a 2-year history of progressive facial hemiatrophy involving the right side of the chin and tongue, associated with mastigatory spasm. Neurological examination showed no abnormalities. Computed tomography and magnetic resonance imaging of the brain and electrophysiological investigations were normal. Histopathological examination of a skin biopsy specimen from the chin revealed atrophy of the subcutaneous fat with homogenization of dermal collagen fibres. Phenytoin 100 mg t.d.s. relieved the mastigatory spasm.