Pretibial epidermolysis bullosa: report of two families and review of the literature

Pretibial dystrophic epidermolysis bullosa: a recessively inherited COL7A1 splice site mutation affecting procollagen VII processing

Pretibial epidermolysis bullosa (PEB) is a rare form of localized epidermolysis bullosa dystrophica (EBD), a heterogeneous group of inherited, blistering diseases characterized by scarring, loss of dermal-epidermal adhesion and altered anchoring fibrils (AF). Mutations in the type VII collagen gene (COL7A1) underlie EBD and in a dominant PEB family a glycine substitution mutation has been identified. We report a 33-year-old man affected by PEB showing abnormal AF and reduced immunostaining for type VII collagen. Mutation search in the COL7A1 gene revealed a 14 bp deletion in the 115 exon-intron boundary (33563del14), which resulted in the in-frame skipping of exon 115 with elimination of 29 amino acids from the pro-alpha1(VII) polypeptide chain. As a consequence, procollagen VII failed to be processed to mature collagen VII and accumulated at the dermal-epidermal junction, as revealed by immunofluorescence staining using a NC-2 domain-specific antibody. The proband's father was a clinically unaffected heterozygous carrier of mutation 33563del14, whereas the maternal pathogenetic mutation has still not been identified. This represents the first report of a recessive deletion mutation in PEB and extends the range of EBD phenotypes associated with mutation 33563del14.

Epidermolysis bullosa pruriginosa: dystrophic epidermolysis bullosa with distinctive clinicopathological features

We report a study of eight unrelated adult patients with a highly distinctive phenotype of dystrophic epidermolysis bullosa. It is characterized clinically by pruritus, lichenified or nodular prurigo-like lesions, violaceous linear scarring, occasional trauma-induced blistering, excoriations, milia, nail dystrophy and, in some cases, albopapuloid lesions on the trunk. The scarring is most evident on the limbs, particularly on the shins, with relative sparing elsewhere. Intact blisters are rarely seen. Physical signs were present at birth in three patients, but in the others skin manifestations were first noticed between 6 months and 10 years of age. Five cases are sporadic, but three of the eight patients have a history of familial involvement, with autosomal dominant inheritance in two cases and recessive transmission in the other case. Studies of the dermal-epidermal junction showed alterations in the number and ultrastructure of anchoring fibrils in lesional, perilesional and non-lesional skin, consistent with a diagnosis of dominant or localized recessive dystrophic epidermolysis bullosa. These patients represent an unusual, poorly recognized form or expression of dystrophic epidermolysis bullosa which has features in common with a variety of acquired inflammatory dermatoses.

Pretibial epidermolysis bullosa: a clinicopathologic study

BACKGROUND

Pretibial epidermolysis bullosa (PEB) is a rare variant of dystrophic epidermolysis bullosa (DEB) that predominantly involves the pretibial skin.

OBJECTIVE

We report 19 cases of DEB with pretibial predilection and our findings on anchoring fibrils.

METHODS

Patients with blisters and scars that primarily involved the pretibial were selected. Blisters and noninvolved skin were studied by light and electron microscopy. Anchoring fibrils were quantified by morphometry.

RESULTS

There were 19 patients from 13 families. The inheritance was autosomal dominant in 10 families and sporadic in one family, and sibling involvement was present in two families. Nail dystrophy was noted in all patients. Pruritus was a common feature. Extensive prurigo occurred in four patients. Eight patients had skin lesions that exclusively affected the legs and were diagnosed as PEB. The remaining patients also showed some albopapuloid or hypertrophic scars at sites other than the leg, features seen in the albopapuloid or Cockayne-Touraine types. These were labeled as albopapuloid PEB or Cockayne-Touraine PEB. Common ancestry and various combinations of PEB, with albopapuloid or Cockayne-Touraine type of EB, were noted in some families. Compared with normal controls, the anchoring fibrils were rudimentary and sparser in both lesional and nonpredilected normal skin, although in the latter the changes were less marked in PEB than in the albopapuloid or Cockayne-Touraine types.

CONCLUSION

Common ancestry may contribute to the higher incidence of DEB, especially PEB, in Tainan, Taiwan. The abnormalities of anchoring fibrils were not restricted to the predilected site in PEB and did not distinguish PEB from other types of DEB.

Pretibial epidermolysis bullosa: report of a case

Pretibial epidermolysis bullosa is a rare variant of hereditary epidermolysis bullosa that is characterized by the delayed onset of a blistering eruption limited to the pretibial area. We present a case in a 48-year-old woman. Immunofluorescence mapping demonstrated blister formation below the basement membrane. This was confirmed by ultrastructural investigations that also revealed rudimentary anchoring fibrils similar to those described in the dominant dystrophic forms of epidermolysis bullosa.

Hereditary epidermolysis bullosa

Hereditary epidermolysis bullosa (EB) is a group of disorders of skin characterized by formation of blisters following minor trauma. There are at least sixteen types of hereditary EB. These types are reviewed in this article. There are several classifications of hereditary EB, and they are discussed, as well as current ideas on pathogenesis. Last, the treatment of this often recalcitrant group of diseases is discussed.

Squamous cell carcinoma in dominant type epidermolysis bullosa dystrophica

The unusual genetic disorder epidermolysis bullosa dystrophica has been reported in several patients in whom the chronic cutaneous scars led to the development of cutaneous squamous cell carcinoma. However, only one of these previously reported cases involved the autosomal dominant form of the disease; the remainder occurred in its recessive counterpart. We report the second and third patients with squamous cell carcinoma associated with the dominant form of epidermolysis bullosa dystrophica. In addition, we not only observed the previous electron microscopic findings of decreased numbers of anchoring fibrils beneath the basal lamina but have also noted marked disruption of the basal lamina itself.