[Pseudoporphyria cutanea tarda in hemodialysis patients]

A bullous disease very similar to late onset cutaneous porphyria has been found in approximately 16 percent of the patients on intermittend hemodialysis. The bullae occur during the summer and are situated on exposed areas, particularly hands, head and neck. There is skin fragility and the bullae are transient, giving place to erosions and later to atrophic scarring. Even milia have been observed. Histology reveals a subepidermal bulla, the basis of which consists of spiky papillary dermis. Immunofluorescence shows immunoglobulin depoits in the vessels and basal membrans. All porphyrin measurements are negative. This disorder may be due to the precence of a non porphyrinogenic photosensitizing substance.