Epidermolysis Bullosa Simplex, Generalized

Description

Epidermolysis bullosa simplex (EBS) is a clinically and genetically heterogeneous skin disorder characterized by recurrent blistering of the skin following minor physical trauma as a result of cytolysis within basal epidermal cells. Most forms show autosomal dominant inheritance. The 3 main types include the generalized Koebner form, the more severe generalized Dowling-Meara form (OMIM ), and the localized, mild Weber-Cockayne form (OMIM ) (Fine et al., 2008). All 3 forms can be caused by mutation in the KRT5 or the KRT14 gene. See {601001} for a rare autosomal recessive form caused by mutation in the KRT14 gene.Davison (1965) referred to generalized distribution of bullous vesicles as epidermolysis simplex bullosa. The condition in which bullae were limited to the hands and feet was referred to as the Cockayne type of epidermolysis bullosa (OMIM ).On the basis of an extensive study in Norway and review of the literature, Gedde-Dahl (1971) arrived at a classification of epidermolysis bullosa. EB simplex in this classification encompassed disorders characterized by bulla formation within the epidermis, basal cell vacuolization, and dissolution of tonofibrils on electron microscopy. The generalized Koebner form and the localized Weber-Cockayne type were believed to be allelic. Gedde-Dahl (1981) recognized at least 16 varieties of epidermolysis bullosa and suggested that dominant EB simplex can be clinically and genetically divided into at least 4 types: the generalized Koebner type, the localized Weber-Cockayne type, the mild Ogna type with fragile skin (OMIM ), and a form with mottled pigmentation (OMIM ).Fine et al. (1991) provided a revised classification of the subtypes of inherited epidermolysis bullosa based on clinical and laboratory criteria.

Clinical Features

• Fever
• Hyperkeratosis
• Nail dystrophy
• Nail dysplasia
• Abnormal blistering of the skin
• Palmoplantar hyperkeratosis
• Milia
• Skin vesicle
• Fragile skin
• Mottled pigmentation