Dystrophic Epidermolysis Bullosa Pruriginosa

Dystrophic epidermolysis bullosa pruriginosa is a rare subtype of dystrophic epidermolysis bullosa (DEB, see this term) characterized by generalized or localized skin lesions associated with severe, if not intractable, pruritus.

Epidemiology

Prevalence is unknown. Approximately 100 families or sporadic cases have been reported to date.

Clinical description

While skin fragility and blistering lesions usually manifest in infancy, which heal with atrophic scarring and milia formation, the onset of intense pruritus is frequently delayed until the adolescence or even adulthood. At the onset of pruritus, the clinical picture generally worsens with the development of papules, nodules, lichenoid and hypertrophic lesions in a linear distribution, preferentially in the extensor surfaces of the limbs. Nail dystrophy is usually present.

Etiology

DEB pruriginosa is caused by mutations within the type VII collagen gene (COL7A1). Mutations in this gene lead to an alteration in function or to reduced amounts of collagen VII. This impairs its assembly into anchoring fibrils that anchor the basement membrane to the underlying dermis.

Genetic counseling

Transmission is autosomal dominant (DDEB pruriginosa) or autosomal recessive (RDEB pruriginosa).