Isotretinoin dermatitis simulating acute pityriasis rosea.

A pityriasis rosea-like eruption developed in two acne patients receiving isotretinoin and gradually resolved once the dosage was reduced. Histologically the lesions, which were characterized by psoriasiform hyperplasia, bore no resemblance to pityriasis rosea. We believe the eruptions were a side effect of isotretinoin therapy.