Inflammatory skin reaction in a previously irradiated body site subsequent to drug administration.
Incidence is not exactly known and retrospective studies suggest a range of 13-49%.
May occur days to years after radiation exposure.
Pathophysiology is unknown
Duration between radiation and drug exposure is most severe when the time interval is short.
Usually associated with chemotherapy including dactinomycin, anthracyclines, bleomycin, alkylating agents, plant alkaloids, docetaxel, platinum drugs.
May occur on first exposure to a drug, but can follow sensitization with a drug that has been administered multiple times.
Non-chemotherapy drugs associated include antituberculosis drugs, antiestrogens, simvastatin, and alpha-interferon .
The reaction affects skin, or other organs, that were previously quiescent and and appeared normal.
Can affect other sites than skin and includes bowel, lungs, esophagus and vaginal mucosa.