Periungual Warts

Authors:
Alexander K. C. Leung, MD
University of Calgary, Alberta, Canada

Benjamin Barankin, MD
Toronto Dermatology Centre, Toronto, Ontario, Canada

Citation:
Leung AKC, Barankin B. Periungual warts. Consultant for Pediatricians. 2016;15(3):136-138.

A 17-year-old young adult presented with hyperkeratotic papules that had coalesced into a plaque on the periungual region of right middle finger. They had been present for approximately 10 months. The lesion was asymptomatic. The patient had a habit of nail biting. Family history was negative for similar skin lesions.

Physical examination revealed multiple, whitish to yellowish, hyperkeratotic papules on the tip of and around the medial nail fold of the right middle finger. Tiny black dots were visible on the surface of the lesion. There was an absence of skin lines crossing the verrucous surface. No similar lesions were observed elsewhere on the body. The rest of the examination findings were unremarkable.

Based on the appearance and location of the lesion, a clinical diagnosis of periungual wart (verruca) was made. The patient was treated with liquid nitrogen by canister every 2 weeks and home therapy with a salicylic acid preparation; after approximately 4 months of treatment, the wart resolved.

Periungual warts are warts that cluster around the fingernail or toenail. They may extend under the nail plate and may lie adjacent to the nail matrix. Periungual warts pose a management challenge because of poor accessibility, recalcitrance, the possibility of cosmetic disfigurement of the nail, and a high recurrence rate.¹

Periungual warts most often are caused by human papillomavirus (HPV) types 1, 2, and 4 that are trophic to the epithelial tissues of the human skin.²

HPV is transmitted by close physical contact, including person-to-person contact and autoinoculation. The virus, however, does not seem to spread to histologically dissimilar sites, such as the oral cavity and genitalia. Moist environments and disruption of epidermal barrier increase the chance of infection. Children with a family member or classmates with periungual warts have a higher risk of developing warts themselves. The risk of developing periungual warts is increased by trauma to the area, such as cuticle picking and nail biting. Although the condition primarily is seen in healthy individuals, those with atopic dermatitis and immunodeficiency are at increased risk.³

Typically, periungual warts present as multiple, firm, rough, yellow-brown or flesh-colored papules that may coalesce into a cauliflower-like plaque with the lesions around a nail. They may become fissured, as illustrated in the case presented here, and thus can be somewhat sore. The absence of dermatoglyphics crossing the verrucous surface is characteristic.² Tiny black dots may be visible at the surface of the wart; these black dots represent thrombosed, dilated capillaries and are pathognomonic of warts. The lesions generally are asymptomatic but can be painful when compressed.⁴ The wart may extend around and underneath the nail plate. Thus, what appears to be a small periungual wart actually may have a large subungual component.

The diagnosis is mainly clinical, based on typical morphologic features. If the diagnosis is in doubt, scraping off the hyperkeratotic surface of the lesion reveals thrombosed capillaries. The diagnosis can be aided by dermoscopy, which will reveal homogeneous black to red dots with globules.⁵

Periungual warts can be painful and cosmetically unsightly, and they can damage the nail bed, distort the nail, create fissures, and lead to paronychia.⁴ Affected individuals can spread the disease to others or themselves (autoinoculation). As such, patients should avoid touching warts on themselves or on others. Periungual warts caused by high-risk HPV types such as HPV 16 pose a risk for malignant transformation into squamous cell carcinoma, although HPV typing is not performed in the routine clinical setting.⁶

Periungual warts are notoriously difficult to treat, and recurrences are common.² Treatments options include liquid nitrogen cryotherapy, electrocoagulation, carbon dioxide or pulsed dye laser therapy, photodynamic therapy with methyl 5-aminolevulinic acid, oral cimetidine, intralesional bleomycin, topical cantharidin, topical diphenylcyclopropenone, topical cidofovir, topical imiquimod, and topical podophyllin alone or in combination with salicylic acid.^1,4,7-10 The choice of treatment method depends on the clinician’s comfort level with the various treatment options, the patient’s age, the number and severity of lesions, the availability of treatment facility, and the preference of the child and parents.

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