Clinical features:
(1) hemodialysis for chronic renal failure
(2) bullous lesions on sun-exposed skin, especially the back of the hands and fingers
(3) healing of the bullae with scarring
(4) increased skin fragility
(5) normal serum, stool and urine levels of porphyrins
Biopsy of a bulla shows:
(1) subepidermal separation
(2) hypogranular mast cells
(3) thickened venule walls
(4) immunoglobulin deposits outside of the venules
Differential diagnosis:
(1) porphyria cutanea tarda
(2) porphyria
(3) drug-induced bullous disease (furosemide, tetracycline, etc)
(4) allergic reaction
