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Sir,

Epidermolysis bullosa (EB) is a rare hereditary disorder of childhood characterized by skin fragility and blister formation.1 Aplasia cutis congenita (ACC) is a rare clinical condition in which localized or widespread areas of skin are absent at birth. Both diseases are also part of Bart syndrome (BS), which is clinically characterized by congenital localized absence of skin, mucocutaneous blistering lesions, and nail abnormalities.2

A female newborn presented at birth with a skin defect on her right lower limb. On physical examination, she had a skin absence with sharply demarcated borders covered by a red ultrathin translucent membrane with 15 × 6 cm localized to the anterior aspect of the right leg, consistent with ACC (Fig. 1a). The lesion extended to the dorsum and plantar surface of the right foot. Hypoplasia and anonychia of the homolateral hallux was observed as well as blisters on the oral mucosa (Fig. 1b). She was born via Cesarean section after 39 weeks gestation without complications in the antenatal period. There was no familiar history of blistering disorders, and her parents were not consanguineous. New blisters appeared on the third day, and a biopsy was performed. Hematoxylin–eosin stain revealed a subepidermal blister with a hemorrhagic content, and the adjacent dermis had a discrete inflammatory infiltrate (Fig. 2a). Immunohistochemical studies with antibodies against laminin-5 showed a normal expression of this antigen (Fig. 2b). Direct immunofluorescence revealed the absence of type VII collagen (Fig. 1c). Those features were consistent with a recessive dystrophic EB (RDEB). Systemic gentamicin and flucloxacillin had been empirically initiated by pediatrics despite the absence of clinical infection and were discontinued five days later. Treatment of the ACC lesion was managed with topical fusidic acid and use of an atraumatic dressing. Complete healing with prominent milia was observed after three months; however, recurrent blistering occurred in the lesion area during this period. After eight months of follow-up, possible extracutaneous involvement was limited to one episode of hematochezia.

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Figure 1.  Aplasia cutis (a) and hypoplasia and anonychia of the hallux (b)

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Figure 2.  Hematoxylin–eosin stain (× 100): subepidermal blister with a hemorrhagic content (a). Immunohistochemical study with antibodies against laminin-5 (b) (× 100). Direct immunofluorescence: absence of type VII collagen (c) (× 100)

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The association of EB, ACC, and nail abnormalities (congenital absence, nail dystrophy, or further loss) was first described by Bart et al.2 in 1966. In BS, the ultrastructural findings observed in ACC areas have revealed the same pathogenic changes as ones observed in associated blisters, supporting that ACC in those patients is an in utero manifestation of EB.3 The diagnosis of ACC is primarily clinical, and ACC associated with EB is classified as type 6 ACC.4 EB comprises a heterogeneous group of mechanobullous diseases that differ with regard to genetic, clinical, and ultrastructural characteristics. Those inherited disorders are characterized by increased skin fragility and blister formation.1 Both autosomal dominant and recessive forms of dystrophic EB result from mutations in the COL7A1 gene, which encodes type VII collagen (component of anchoring fibrils).5 The type of inherited EB is established by demonstration of characteristic ultrastructural features by transmission electron microscopy or by immunofluorescence antigenic mapping and EB-related monoclonal antibody studies. In our case, a negative family history combined with the demonstration of a normal expression of laminin-5 in the blister roof (the antigen is localized in the lower portion of the lamina lucida), and the complete absence of type VII collagen during direct immunofluorescence allowed the precise characterization of the EB subtype. A review of the literature showed that presentation of RDEB with ACC is a very rare condition, and to the best of our knowledge, only seven cases have been reported.1,6,7 Extracutaneous involvement is frequent in RDEB. The gastrointestinal tract and ocular and genitourinary mucosa can be affected. An accurate classification of the EB subtype is important to define prognosis and genetic counseling.

Acknowledgments

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  2. Acknowledgments
  3. References

We wish to thank Dr. Stéphanie Leclerc-Mercier (Department of Pathology, Necker-Enfants Malades Hospital Paris, France), for the histopathological examination.

References

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  2. Acknowledgments
  3. References
  • 1
    McCarthy MA, Clarke T, Powell FC. Epidermolysis bullosa and aplasia cutis. Int J Dermatol1991; 30: 481484.
  • 2
    Bart BJ, Gorlin RJ, Anderson VE, Lynch FN. Congenital localized absence of skin and associated abnormalities resembling epidermolysis bullosa. Arch Dermatol1966; 93: 296304.
  • 3
    Kanzler MH, Smoller B, Woodley DT. Congenital localized absence of the skin as a manifestation of epidermolysis bullosa. Arch Dermatol1992; 128: 10871090.
  • 4
    Frieden IJ. Aplasia cutis congenital: a clinical review and proposal for classification. J Am Acad Dermatol1986; 14: 646660.
  • 5
    Vardi R, Sadowski S, Uitto J, Pfender E. Epidermolysis bullosa. II. Type VII collagen mutations and phenotype-genotype correlations in the dystrophic subtypes. J Med Genet2007; 44: 181192.
  • 6
    Wojnarowska FT, Eady RA, Wells RS. Dystrophic epidermolysis bullosa presenting with congenital localized absence of skin: report of four cases. Br J Dermatol1983; 108: 477483.
  • 7
    Medenica L, Lens M. Recessive dystrophic epidermolysis bullosa: presentation of two forms. Dermatol Online J2008; 14: 2.