Jump To As many as 95% of people receiving radiation treatment for cancer experience radiation dermatitis, a type of skin inflammation sometimes referred to as a radiation burn. Radiation dermatitis (or radiodermatitis) can appear within one to four weeks after starting treatment, and may first resemble a mild sunburn: redness, irritation, or even minor skin peeling, said Rohini Bhatia, MD, an assistant professor of radiation oncology at Emory University’s Winship Cancer Center.