Absent Skin and Butterfly Children: A Sporadic Case of Bart Syndrome

Abstract

A full-term male infant with a history of in utero exposure to cocaine and alcohol was born with circumferential bilateral lower extremity ulcerations and skin hypoplasia over the same region (Figure). Upon light touch of these lesions, the infant became restless and fussy. A thorough dermatologic physical examination revealed dystrophy of several toenails involved with the ulcerations. Two punch biopsies from distinct areas of the margin of the ulceration revealed a central area of thin epidermis with underlying elastolysis, fibrosis, and an absence of adnexal structures that was consistent with aplasia cutis congenita. The rest of the biopsy showed adnexal structures and overlying subepidermal split with minimal inflammation suggestive of epidermolysis bullosa (EB). Aplasia cutis congenita with EB and nail dystrophy is highly suggestive of the clinical variant of EB, Bart syndrome. Genetic testing showed heterozygosity for p.Gly2043Arg (GGG>AGG): c.6127 G>A in exon 73 of COL7A1, the variant responsible for dominant dystrophic EB. The patient's parents were negative for the mutation. COL7A1 is expressed in basal keratinocytes of the epidermis and encodes for type VII collagen fibrils that stabilize the skin's structural integrity. 1 Pathogenic variants lead to the blistering of EB. 2 Genetic testing is currently the gold standard given the increasing prevalence of EB. 3 Aplasia cutis congenita, the congenital absence of dermis and epidermis, can be diffuse or localized, and is most commonly located on the scalp. Its etiology is unknown but may be multifactorial, involving genetics, teratogens, or vascular compromise. It may be solitary or present as a syndrome associated with skin and/or mucosal fragility. 4 Bart syndrome is the triad of congenital localized absence of the skin (aplasia cutis), mucocutaneous blisters, and nail deformities inherited in an autosomal dominant manner. Sporadic mutations involving COL7A1 may be seen, as with this patient. The aplasia cutis associated with Bart syndrome usually resolves with proper wound care over 6-8 weeks, granulating in with scarring. 5 Dominant dystrophic EB, however, remains a lifelong challenge. Those afflicted with the disease are often called "butterfly children" in popular media due to the delicate nature of their skin. Skin fragility and bullae are common on acral surfaces and the extremities, especially when children attain mobility. When blisters form, they should be punctured with a sterile needle and covered with petrolatum gauze. Open wounds can be managed with nonadherent dressings and topical or oral antibiotics as required, while modalities applying pressure, such as tape, can precipitate further blisters and should be avoided. Scarring over joints further restricts range of motion and necessitates appropriate physical therapy. 6 Caregiver education is the single most important intervention in minimizing bullae formation, life-threatening infection, and scarring. The patient's mother has since been able to intervene appropriately, and the disease has...

Conservative Management of a Rare Entity—Aplasia Cutis Congenita: A Case Report

“…EB is also a rare, inherited, entity characterized by blister formation due to skin fragility (Cohn & Teng, 2016). The association of ACC and EB is commonly known as Bart syndrome, but the use of this term is problematic because ACC may precede all kinds of EB (Bart et al, 1966; Benvenuto et al, 2003; McGowan et al, 2020).…”