A Rare Case of Suspected Dystrophic Epidermolysis Bullosa Pruriginosa

ABSTRACT

Inherited epidermolysis bullosa (EB) encompasses over 30 phenotypes or genotypes. A characteristic feature of all types of EB is the presence of recurrent blistering or erosions, the result of even minor traction to this tissues. There are four major types of inherited EB EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB), and Kindler syndrome. These differ not only phenotypically and genotypically but more importantly by the site of ultrastructural disruption or cleavage. Dystrophic epidermolysis bullosa (DEB) is a rare mechanobullous genodermatosis inherited either with autosomal dominant or recessive pattern and characterized by fragility, blistering and scarring of the skin and mucous membranes. Blistering is due to abnormalities in anchoring fibrils (AF), microstructures mainly composed of type VII collagen (COLLVII), which contributes to the maintaining of dermal-epidermal adhesion. Most cases are sporadic, but a few show autosomal dominant or autosomal recessive pattern of inheritance. Microscopic studies of EB pruriginosa show typical findings of dystrophic EB, and it has been postulated that itching lesions of EB pruriginosa could represent an abnormal dermal reactivity of some subjects to their inherited bullous disorder. The study of the molecular basis of dominant dystrophic EB (classical) and EB pruriginosa shows that both diseases are caused by a missense glycine substitution mutation by different amino acids in the same codon of COL 7A (G2028R and G2028A)