tokens: Epidermolysis bullosa is clinically and genetically very heterogeneous , being classified into four main types according to the layer of skin in which blistering occurs : epidermolysis bullosa simplex ( intraepidermal ) , junctional epidermolysis bullosa ( within the lamina lucida of the basement membrane ) , dystrophic epidermolysis bullosa ( below the basement membrane ) , and Kindler epidermolysis bullosa ( mixed skin cleavage pattern ) .