Facial pyogenic granuloma-like lesions under isotretinoin therapy

A male patient with severe cystic acne was treated with 13-cis-retinoic acid in a dosage of 1 mg/kg/day. Early flare-up of his acne and multiple pyogenic-like lesions on his face appeared during the second week of isotretinoin treatment. Histologic study of the lesions revealed granulation tissue. Possible etiologies for this phenomenon are discussed.