Acquired pili torti in two patients treated with synthetic retinoids.

A mother and daughter with epidermolytic hyperkeratosis were treated with two different synthetic retinoids at different times. Both patients exhibited the previously unreported side effect of increased curliness of scalp hair. Light microscopic examination revealed pili torti during the administration of isotretinoin. Both patients also experienced a better therapeutic response to and more hair loss with etretinate than with isotretinoin.