Localized acne induced by radiation therapy.

The appearance of localized acne or comedo reaction during or shortly after radiotherapy is an unusual adverse event, but one that is probably underestimated. It can manifest as an inflammatory (papules, pustules, nodules), comedonal (open and closed comedones, Favre-Racouchot-like syndrome), or mixed presentation. We report two new cases of radiation-induced acne with different clinical aspects and discuss the main known features of this adverse event.