Recessive dystrophic epidermolysis bullosa inversa (RDEB-I) is rare subtype of dystrophic epidermolysis bullosa (DEB, see this term) characterized by blisters and erosions which are primarily confined to intertriginous skin sites, the base of the neck, the uppermost back, and the lumbosacral area.
Less than 100 cases have been reported to date.
The disease manifests at birth or shortly thereafter with generalized blistering and superficial erosions that heal with atrophic scarring and milia formation. After the first years of life, blistering tends to localize to folds, particularly axillae, inframammary folds and groins, as well as to the base of the neck, the uppermost back, and the lumbosacral and perianal area. Nail dystrophy is typical but of variable severity. Lesions of the oral cavity are always present and can lead to microglossia (loss of lingual papillae and fusion of the tongue to the mouth floor) and ankyloglossia (obliteration of the oral vestibules and progressive restriction of oral aperture). Esophageal involvement is often severe and is associated with a risk of esophageal stricture (10% and 90% by ages 5 and 30, respectively) that can impair intake of nutrients. Lesions of the lowermost portion of the genitourinary tract are also common and may lead to the development of vaginal strictures that may impair normal sexual function. Other less common extracutaneous features are observed and include external auditory canal stenosis with some degree of hearing loss, corneal erosions, and anemia. Growth delay is rare. Patients may develop squamous cell carcinomas, with a cumulative risk reaching 23% by age 50 (U.S. EB national registry) which is much lower than in either of the two generalized subtypes of RDEB (RDEB-sev gen and RDEB-other; see these terms).
The disease is caused by mutations in the type VII collagen gene (COL7A1). Mutations in this gene lead to an alteration in function or reduced amounts of collagen VII. This impairs collagen VII assembly into anchoring fibrils which anchor the basement membrane to the underlying dermis. This in turn causes reduced skin resistance to minor trauma.
Transmission is autosomal recessive.
Last update: March 2013