Development of folliculitis and pyoderma gangrenosum in association with abdominal pain in a patient following treatment with isotretinoin.

A 19-year-old man with severe acne developed extensive scalp folliculitis and later superficial pyoderma gangrenosum following treatment with isotretinoin. A cyclical neutropenia was noted and bone marrow findings suggested myelodysplasia. We believe that isotretinoin was implicated in the development of overt symptoms in this patient whose haematological condition was previously asymptomatic.