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Painless genital papules and plaques

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Painless genital papules and plaques
Capt Jessica L Berryman MC, Maj Terri J Nutt MC, LTC Stephen C Groo MC
Dermatology Online Journal 14 (2): 7

David Grant Medical Center, Travis AFB, CA, and Madigan Army Medical Center, Fort Lewis, WA

Epidermolytic hyperkeratosis (EH) is an abnormality of the epidermal maturation process associated with mutations in keratins. This is typically seen in keratins 1 and 10 and may be an acquired or a congenital defect. The term epidermolytic acanthoma is typically used to signify a solitary discrete epidermal proliferation characterized by EH. The histological characteristics typically include prominent epidermolytic degeneration of the keratinocytes of the upper layers of the stratum spinosum and stratum granulosum. The typical pattern of distribution for these lesions is the trunk, scrotum, or light exposed skin of middle-aged individuals. Epidermolytic acanthomas confined to the penile shaft have not previously been reported in the literature. Genital EH is rare in itself, but is more common in males with a predilection for the scrotum [1]. We present a unique case of lesions confined to the penile shaft.

Figure 1Figure 2

A 24-year-old male presented with a 3-year history of multiple lesions isolated to his penis. The lesions appeared around the same time, were asymptomatic, and remained fixed in the same location. He had no relevant personal history and was not on any medications. He denied history of genital warts or sexually transmitted diseases. He had been seen by his primary care physician and treated with liquid nitrogen without success. On physical examination the patient had 5 skin-colored rough surfaced papules and plaques on the right side of the shaft of his penis. A shave biopsy of one of the lesions was sent for histopathologic examination with the diagnosis of epidermolytic acanthomas. Histopathologic examination of the biopsy specimen showed mild epidermal acanthosis and papillomatosis with epidermolytic hyperkeratosis (orthokeratotic, without parakeratosis). There was marked granular degeneration of the cells in the stratum spinosum, sparing the basal layer. Edema and coarse keratohyalin granules extended deeply into the epidermis. There was no histologic evidence of human papilloma virus. In-situ hybridization studies for human papilloma virus types 6/11, 16/18, and 31/33/51 were negative. The diagnosis of epidermolytic acanthoma was made. Our patient was treated initially with cryotherapy followed by emollient creams.

The etiology of epidermolytic acanthoma is largely unknown. In clinical appearance the lesions are verrucous but do not contain human papillomavirus DNA. An abnormality in keratin 1 and keratin 10 gene expressions in the lesions of epidermolytic acanthomas has been demonstrated [2]. Possible etiologies reported in the literature include trauma [3], severe sunburn [4], and immunosuppression [5].

Treatment options for genital epidermolytic acanthomas include emollients, or weak preparations of lactic acid, salicylic acid or glycolic acid. Occasionally destructive methods may be used to include curettage or liquid nitrogen. Aggressive treatment increases the risk of prolonged healing time in the denuded area.

Our patient's lesion is unique in that there is no reported history of trauma, repetitive scratching, sun exposure, or immunosuppression. The variability in the literature of the number of lesions and the sites affected suggest that many factors are likely involved in the pathogenesis of these lesions.


1. Banky JP, Turner RJ, Hollowood K: Multiple scrotal epidermolytic acanthomas; secondary to trauma? Clinical and Experimental Dermatology 2004;29:489-491.

2. Cohen PR, Ulmer R, Theriault A, Leigh IM, Duvic M: Epidermolytic acanthomas: Clinical characteristics and immunohistochemical features. Am J Dermatopathol 1997;19:232-241.

3. Sanchez-Carpintero I, Espana A, Idoate MA: Disseminated epidermolytic acanthoma probably related to trauma. Br J Dermatol 1999;141:728-730.

4. Metzler G, Sonnichsen K: Disseminated epidermolytic acanthoma. Hautarzt 1997;48:740-742.

5. Chun SI, Lee JS, Kim NS, Park KD: Disseminated epidermolytic acanthoma with disseminated superficial porokeratosis and verruca vulgaris in an immunosuppressed patient. J Dermatol 1995:22:690-692.

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