Mechanism of Blister Formation in Porphyria Cutanea Tarda: I. Histopathological Observation of Blisters in Three Cases of Porphyria Cutanea Tarda

We performed a histopathological investigation of the bullous lesions in 3 cases of porphyria cutanea tarda. All cases showed subepidermal bullae by light microscopy. PAS positive materials were present on the roof of the bullae and partially present on their bases. Electron-microscopically, the basal lamina was clearly recognized on the base. From these results, we suggest that the blister in porphyria cutanea tarda occurs initially within the junctional zone; this initial bulla may quickly change into a dermolytic bulla with additional stimulation.