1 yr old with hyperkeratotic lesions in the axilla and on thighs distributed along Blaschko lines

    Nevoid epidermolytic hyperkeratosis

    Clinical features:

    • Presents at or shortly after birth with blistering
    • With time skin becomes keratotic, verrucous
    • Shedding of hyperkeratotic masses results in circumscribed islands of normal-appearing skin
    • Involvement of flexural areas
    • Palmar and plantar involvement in the PS subtypes
    • Secondary pyogenic infections

    Mode of Inheritance:

    • Autosomal Dominant
    • Defect in the genes for keratin 1 and keratin 10
    • Causes dysfunction of keratin intermediate filaments which weakens the structurals stability of the keratinocytes

    Frequency:

    • One case per 200,000-300,000 persons

    Histological features:

    • Hyperkeratosis, papillomatosis, acanthosis
    • Giant, coarse keratohyalin granules
    • Vacuolization of the granular layer, resulting in cell lysis and subcorneal multiloculated blisters
    • Occasionally, deeper granular cells become dense, enlarged, and irregular, and the shaped masses appear to be keratohyaline granules.


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