Multiple subtypes are defined, based on features such as Distribution of lesions (localized vs generalized) Relative cutaneous vs extracutaneous severity Other skin findings (eg, exuberant granulation tissue, mottled pigmentation, pseudosyndactyly [fusion of skin between digits]) Mode of inheritance (autosomal dominant vs autosomal recessive) Specific genes involved (See table Some Features of the Major Epidermolysis Bullosa Types.)