Abnormal blistering of the skin Blistering by histological location 2021-05-08T14:55:16Z Blistering (presence of multiple fluid filled blisters) categorized according to the layer of the skin in which the blister originates. The skin is divided into three layers. The epidermis (outermost layer, which mainly consists of keratinocytes), the dermis, and a subcutaneous layer. The epidermis is divided into five layers: the basal lamina (innermost layer), the basal cell layer, the stratum spinosum, the stratum granulosum, and the stratum corneum (outermost layer). Cleavage in epidermolysis bullosa (EB) simplex occurs within the basal keratinocytes; in junctional EB, within the lamina lucida; and in dystrophic EB occurs in the sublamina densa, in the upper portion of the dermis (papillary dermis). In Kindler's EB, cleavage can occur in the basal keratinocytes, in the lamina lucida, or below the lamina densa.