What is epidermolysis bullosa?

This is a group of diseases with inherited defects in the skin that result in blistering spontaneously or after minor trauma. Many subtypes have been described (Table 10-6):

• Epidermolysis bullosa simplex, an autosomal dominant trait, begins at birth or early in childhood, with blisters due to mild trauma that heal without scarring.
• Junctional epidermolysis bullosa also typically begins at birth and may present with generalized blistering. The blisters occur at the dermal–epidermal junction and are due to molecules involved in anchoring the epidermis to the dermis. This type of epidermolysis bullosa may be inherited as an autosomal recessive trait.
• Dystrophic epidermolysis bullosa may be autosomal dominant or recessive in inheritance. It ranges from mild to severe blistering that can be disfiguring. It is due to a defect in the dermal anchoring fibrils (type VII collagen). For all types of epidermolysis bullosa, skin biopsies for routine histology (sometimes with immunoperoxidase stains to type IV collagen to detect the level of the split), as well as electron microscopy, are often required for diagnosis. Referral to a center specializing in epidermolysis bullosa is optimal, and also the National Epidermolysis Bullosa Registry (telephone: 919-966-2007) may be contacted.
  
  

 

Table 10-6. Subtypes of Epidermolysis Bullosa
	DISEASE		DEFECT		LEVEL OF SPLIT
	EB simplex		Keratins 5 and 14		Basal keratinocytes
	EB simplex with muscular dystrophy EB simplex with pyloric atresia EB simplex, Ogna type EB simplex, Dowling-Meara type		Plectin		Intracytoplasmic plaque of hemidesmosome
	Junctional EB, Herlitz Junctional EB, non-Herlitz (GABEB) Junctional EB with pyloric atresia		Laminin components α3, β3, α2 BP180 (COLXVIIa1) Laminin components α3, β3, γ2 Integrins α6, β4		Lamina densa/lucida interface Lamina lucida Lamina densa/lucida interface Lamina lucida/hemidesmosome
	Dystrophic EB		Type VII Collagen (COL VIIa1)		Sublamina densa