A case of junctional epidermolysis bullosa with prurigo-like lesions and reduction of collagen XVII and filaggrin

Funding sources: L.C. was supported by ‘Kommission Klinische Forschung’ (KKF) of the Technical University Munich and CK Care Foundation, and C.H. by DFG 5663/2‐1. Conflicts of interest: none declared. Madam, Junctional epidermolysis bullosa (JEB) is a group of heterogeneous, autosomal recessive genodermatoses, characterized by blister formation after minor trauma and skin cleavage within the lamina lucida.1 The main subtypes, JEB‐Herlitz and JEB‐other, are caused by mutations in the genes for the laminin 332 chains, or for the transmembrane collagen XVII (COL17A1). Additional rare subtypes are associated with mutations in the genes for the integrin subunits α6, α3 and β4. Collagen XVII is a structural component of hemidesmosomes, multiprotein complexes that mediate adhesion of keratinocytes to the underlying basement membrane. In most cases, JEB‐other is associated with null mutations leading to loss of collagen XVII, and is characterized by generalized blisters, atrophic scars and dyspigmentation, partial alopecia, dystrophic nails, mild mucosal involvement and dental anomalies. Missense or splice‐site mutations allowing residual protein expression may cause milder and/or localized phenotypes.2, 3