Dr Hilary Brown, General Practitioner, Newcastle Skin Check, Newcastle, NSW, Australia. DermNet Editor in Chief: Adjunct A/Prof Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy edited by Gus Mitchell. September 2019.
EB with congenital absence of skin was originally described by Bart in 1966 after observing a family with congenital absence of skin on the lower leg, widespread blistering affecting the skin and mucous membranes, and nail dystrophy . In 1986, Frieden proposed a classification of aplasia cutis congenita in which conditions were classified into nine groups according to location and presence of other anomalies . Bart syndrome was classified as type VI aplasia cutis congenita by its combination of a congenital localised absence of skin, epidermolysis bullosa, and nail dystrophy.
In 2014, a working group of experts in EB suggested a new classification of EB based on molecular features . They suggested the substitution of eponymous names with descriptive terms and recommended Bart syndrome be known as EB with congenital absence of skin.
EB with congenital absence of skin is rare and the exact incidence is unknown. Aplasia cutis congenita is seen in 1–2 per 10,000 births .
EB with congenital absence of skin can be considered a rare form of aplasia cutis congenita, but the proportion of aplasia cutis congenita which can be classified as EB with congenital absence of skin is unknown.
EB with congenital absence of skin is a familial condition with an autosomal dominant pattern of inheritance. Isolated cases have also been recognised .
Its aetiology and pathogenesis are still controversial. The genetic abnormality has been associated with chromosome 3 [6,7].
EB with congenital absence of skin is a clinical triad.
The areas of absent skin are usually unilateral and involve the medial and/or dorsal surface of the lower limb. They are sharply demarcated, glistening red areas of ulceration that extend upward from the dorsal and medial surface of the foot and shin .
EB with congenital absence of skin may also be associated with other anomalies, such as:
Complications of EB with congenital absence of skin include infection and haemorrhage. Hypothermia, hypoglycaemia, and disorders of fluid balance may complicate large defects [4,8].
EB with congenital absence of skin is a clinical diagnosis. Histological evaluation of the skin can help to confirm the diagnosis.
Biopsy reveals a subepidermal blister with an inflammatory infiltrate in the dermis . In some cases, electron microscopy findings of separation of the dermal-epidermal junction and interruption of the basal lamina are similar to that seen in junctional EB . Other case studies have shown the split in the skin to be below the lamina densa on electron microscopy .
The differential diagnoses of EB with congenital absence of skin include:
The management of EB with congenital absence of skin is usually conservative. The aim is to accelerate healing of the affected portions of the skin, to prevent infection or other complications, and to reduce the risk of scarring.
Topical antibacterial ointment and wet dressings are the mainstays of treatment . Prophylactic systemic antibiotics are not recommended. Occasionally surgical intervention with a skin graft or flap repair may be needed for a large defect .
In general, the prognosis of EB with congenital absence of skin is good. Most cases heal well within months with no long-term sequelae .
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