Histologic examination of the specimen from the right thumb revealed a subepidermal vesicle with minimal lymphocytic infiltration. The roof of the vesicle showed a component of necrosis over the central portion of the lesion. The dermal papillae in these sections showed a pattern of preservation (festooning). Direct immunofluorescence analysis revealed homogeneous deposits of lgG, IgA, IgM, C3, and fibrin in the superficial dermal vessel walls. Faint linear staining with IgG at the dermal-epidermal basement membrane was also noted. The results of 24-hour urine porphyrin studies were negative.
Recurrent Blisters on the Hands and Face. Arch Dermatol. 2002;138(12):1607. doi:10.1001/archderm.138.12.1607