• A skin biopsy specimen was obtained from a 1-month-old female with epidermolysis
bullosa simplex (Koebner). Histologically, an intraepidermal separation was seen and
considered to be formed by cytolysis of the epidermal basal cells. Ultrastructurally, the basal
cells were lacking in cytoplasmic tonofilaments, and the initial change of the cytolysis
seemed to be cleavages of the cytoplasm. Immunohistochemically, a basal cell keratin was
expressed in a suprabasal cell layer but not in the basal cell layer, and a panepithelial …