One day after sunbathing, a breast cancer patient received intravenous methotrexate, cyclophosphamide and 5-fluorouracil and had a recall of her UV erythema over the following week. Phototesting with UVA and UVB prior to and after a subsequent chemotherapy treatment showed a UVB-induced recall of erythema, as well as a phototoxicity-like response. Skin biopsies from test sites were compatible with phototoxic dermatitis. The occurrence of both erythema recall and the phototoxicity-like reaction suggests that more than one mechanism is involved in this side effect.
Photo-dermatology, 1984, Vol 1, Issue 3, p. 129-32