Radiation recall dermatitis induced by a second course of radiation therapy in the absence of clinically significant field overlap

Radiation recall is a phenomenon wherein an acute inflammatory reaction occurs in a previously irradiated field upon exposure to a subsequent agent months or even years after radiation therapy. Common causative agents include systemic therapy, such as chemotherapeutics or antibiotics. In the literature, these agents have been reported to trigger a variety of radiation recall reactions, most frequently dermatitis. We present the first documented case of radiation therapy-induced radiation recall dermatitis and postulate a hypothesis for its mechanism of action.