Epidermolysis bullosa simplex: A blistering skin condition usually inherited as an autosomal dominant disease. The faulty genes are those that provide instructions for producing keratin, a fibrous protein in the top layer of skin. As a result, the skin splits in the epidermis, producing a blister.
Epidermolysis bullosa simplex (EBS) usually begins with blistering that is evident at birth or shortly afterward. In a localized, mild form of EBS called Weber-Cockayne, blisters rarely extend beyond the feet and hands. In some subtypes of EBS, the blisters occur over widespread areas of the body.