In this issue of the Archives, Judd et al1 call attention to naproxen as a recent addition to an array of therapeutic agents associated with a pattern of bullous cutaneous phototoxicity that bears strong clinical and histologic resemblance to porphyria cutanea tarda (PCT). Previously reported agents include tetracyclines,2,3 furosemide,4,5 nalidixic acid,6 dapsone,2 and pyridoxine.7 The term pseudoporphyria has been loosely applied to the cutaneous fragility and subepidermal blistering in light-exposed skin reported with exogenous photosensitizing agents, because, despite the many gross and microscopic similarities in lesions of patients with typical PCT, abnormal accumulations of porphyrins, when searched for, were not found in blood, urine, or stool.
The term pseudoporphyria has also been applied to the bullous dermatosis associated with hemodialysis.8,9 In this context, however, participation of porphyrin photosensitization in the development of cutaneous fragility and bullae may have relevance at
Poh-Fitzpatrick MB. Porphyria, Pseudoporphyria, Pseudopseudoporphyria...?. Arch Dermatol. 1986;122(4):403-404. doi:10.1001/archderm.1986.01660160059018