Localized epidermolytic hyperkeratosis of the female external genitalia.

Background:  Epidermolytic hyperkeratosis (EH) is most commonly associated with the diffuse involvement of congenital ichthyosiform erythroderma, but can also be found in a localized pattern. Localized EH is rare, but mucocutaneous lesions have been been identified, most commonly in the mouth. Methods:  We observed a 58-year-old African-American female who noted spots on her genitalia for approximately 2 years. The lesions were increasing in size, darkening, and had become pruritic and sore over the past 6 months. Results:  Physical examination revealed seven scattered, tan to brown, verrucoid papules on the labia and mons pubis, resembling condylomata acuminata or Bowenoid papulosis. Biopsy of a single labial papule revealed epidermal acanthosis, compact hyperkeratotic papillomatosis, perinuclear clear zones, granular keratohyalin clumping, hypergranulosis, and dyskeratosis resulting in intracellular eosinophilic globules, all characteristic of EH. Conclusions:  Because of the rarity of localized genital EH and similar appearance to common diagnoses, clinical confusion may occur without biopsy.