Pretibial epidermolysis bullosa

Abstract

A 37‐year‐old white man with a history of essential arterial hypertension and idiopathic thrombocytopenic purpura (for the latter disorder, oral corticosteroids had been administered successfully), was first examined in our department in June 1997. He had a persistent, pruriginous eruption on the pretibial regions which had been present since the age of 16 years. He complained of bullous lesions after minor trauma to the skin. Examination revealed bilateral, brown, erythematous, shiny, indurated plaques on the anterior regions of his lower legs. Several clear blisters, scars, and excoriations were also present on the left leg ( ). His toenails were thickened and dystrophic, but his teeth and hair were normal. 1 Vesicles, erosions, and crusts on the left leg Histopathologic examination of a vesicle on the left leg revealed a subepidermal blister with sparse perivascular lymphocytic infiltrate in the upper dermis. The contents of the blister were fibrinous ( ). Immunohistochemical study was automatically performed (TechMate 500) with monoclonal antibody to type IV collagen (clone CIU 22, Dako), a component of lamina densa, after enzymatic and heat antigen retrieval. Type IV collagen was present on the roof of the blister, indicating that the blister formation was beneath the lamina densa ( ). Ultrastructural examination showed an intact dermoepidermal junction with normal hemidesmosomes and basal keratinocytes; however, the anchoring fibrils were markedly decreased in number ( ) and were rudimentary. 2 (A) A subepidermal blister covered by intact epidermis and sparse inflammatory infiltrate in the papillary dermis (hematoxylin and eosin, ×100). (B) Immunohistochemical investigation for collagen IV demonstrated that the blister developed beneath the lamina densa (collagen IV, ×200) 3 Ultrastructural examination showed a decreased number of anchoring fibrils in the dermal papillae (×12,000) The father of the patient and the paternal grandfather had a similar blistering eruption on the pretibial areas. His son, a 2‐year‐old boy, also presented bullous lesions on the anterior surface of the legs, with scars and milia. His daughter, a 6‐year‐old girl, was not affected. The pattern of inheritance was autosomal dominant.

Pretibial epidermolysis bullosa: is this case a new subtype with loss of types IV and VII collagen?

“…DEB comprises a group of diseases characterized by blistering of the skin, which heals with scarring. Several subtypes have been described based on the distribution of the lesion, the severity of the disease, and the pattern of inheritance 3 . According to the pattern of inheritance, DEB is divided into dominant and recessive types.…”

“…According to the pattern of inheritance, DEB is divided into dominant and recessive types. Dominant DEB (DDEB) can be divided into generalized (Cockayne–Touraine and Pasini types) and localized (acral or minimus and pretibial variants) forms 3 …”

“…The diagnosis of PEB may be suggested by the clinical features; however, the diagnosis must be confirmed by an ultrastructural study demonstrating a reduced density of AFs 3,7 …”

“…Several subtypes have been described based on the distribution of the lesion, the severity of the disease, and the pattern of inheritance. 3 According to the pattern of inheritance, DEB is divided into dominant and recessive types. Dominant DEB (DDEB) can be divided into generalized (Cockayne-Touraine and Pasini types) and localized (acral or minimus and pretibial variants) forms.…”

“…Dominant DEB (DDEB) can be divided into generalized (Cockayne-Touraine and Pasini types) and localized (acral or minimus and pretibial variants) forms. 3 PEB is a rare form of localized DDEB, first described by Kuske 4 in 1946, which shows recurrent blistering and scarring, predominantly on the pretibial areas. The inheritance pattern is autosomal dominant, except for a few sporadic cases reported in the literature.…”