The hematoxylin-eosin–stained biopsy specimen revealed separation of the keratinocytes at the basal cell layer, with ballooning degeneration. Throughout the dermis and at the blister base, there was a mild inflammatory infiltrate composed of eosinophils and mast cells. Immunohistochemical analysis for collagen IV revealed a linear distribution on the floor of the blister; and for keratin, a continuous band along the basement membrane zone.
Electron microscopy of the gastrocnemius muscle performed at autopsy revealed degenerating and focally atrophic fibers intermixed with normal fibers. (The single arrows in Figure 3 show necrotic keratinocytes, and the double arrows show the basement membrane.) There were empty sarcolemmal membranes, collections of amorphous material, and mitochondria with inclusions. Autopsy also revealed blistering of the tongue and perioral esophagus and an eroded laryngeal mucosa. Pyloric stenosis was not present.
Congenital Erosions. Arch Dermatol. 2001;137(11):1521-1526. doi: