EBS

BCIE

Defect

K5 and K14 keratins

K1 and K10 keratins

Presentation

Tense or flaccid blisters on feet, hands, elbows, and knees in newborns and early infants

Widespread blistering, erythema, and desquamation especially in flexural regions in the newborn. This is replaced by a lifelong ichthyotic, scaly, hyperkeratotic skin disorder after the first few months of life.

Treatment

Saline compresses, topical antibiotics, or topical steroids. Gentle bathing and cleansing followed by protective emollients and non-adherent dressings.

Regimen of daily bathing with moisturizer application twice daily. Alpha-hydroxy acids and poly-hydroxy acids may reduce symptoms of dryness and improve cosmetic appearance with consistent use. Regular shampooing and gentle debridement may reduce scalp scaliness. For severe cases, etretinate may be beneficial.

Histology

Bullae and/or clefting of the stratum basale

Features include cytolysis of basal keratinocytes and clefting of the basal cell layer (+/- variable intermediate filament clumping).

Bullae and/or clefting of the stratum spinosum or stratum granulosum

Features include hyperkeratosis, hypergranulosis, and epidermolysis. Distinct epidermal cells with perinuclear vacuolization (vacuolar degeneration) with indistinct peripheral boundaries are present within areas of epidermolysis. Compact hyperkeratosis, vacuolar degeneration in the upper stratum spinosum and stratum granulosum, filament clumping, a thickened granular layer with irregularly shaped keratohyaline granules, and acantholysis are diagnostic.

Other testing

Transmission Electron Microscopy (TEM)

Indirect immunofluorescence

Genetic testing: KRT 5 and KRT 14

Indirect immunofluorescence

Genetic testing: KRT 1 and KRT 10

Inheritance

AD

AD or sporadic mutation