Localized acneiform eruption following radiotherapy in a patient with breast carcinoma

The vast majority of patients treated with radiotherapy develop dermatological side effects. Acute radiation dermatitis or chronic skin fibrosis are well known sequels of radiation, but there are also other infrequent skin toxicities following external radiotherapy we should be aware of. We present a case of a rare form of delayed radiation dermatitis consisting of a localized acneiform eruption, confirmed by skin biopsy, in the irradiated fields in a woman with breast cancer. We review the clinical characteristics and risk factors available in the literature about this unusual adverse effect of radiotherapy. It is important for dermatologists to recognize this rare adverse effect, owing to the important impact on physical and psychosocial health of the patients and because it may delay the surgical reconstruction.