Erythrokeratodermia variabilis treated with isotretinoin. A clinical, histologic, and ultrastructural study.

A 30-year-old woman with erythrokeratodermia variabilis was treated with oral isotretinoin for four months. Clinical and light and electron microscopic observations were made before and after treatment. A characteristic electron microscopic feature was subnormal numbers of keratinosomes within the stratum granulosum of hyperkeratotic plaques. Isotretinoin therapy resulted in almost complete clinical clearing of these plaques and restoration of normal numbers of epidermal keratinosomes. In addition, distinctive dyskeratotic cells containing clumped tonofilaments were observed within the stratum granulosum by electron microscopy. These cells persisted after retinoid treatment.