Warts - Warts - MSD Manual Professional Edition (2024)

1. 1. Haley CT, Mui UN,Vangipuram R, et al: Human oncoviruses: Mucocutaneous manifestation, pathogenesis, therapeutics, and prevention. Papillomaviruses and Merkel cell polyomavirus. J Am Acad Dermatol 81:1–21, 2019. doi: 10.1016/j.jaad.2018.09.062

Common warts (verrucae vulgaris) are caused by HPV types 1, 2, 4, and 7 and occasionally other types in immunosuppressed patients (eg, 75 to 77).

They are usually asymptomatic but sometimes cause mild pain when they are located on a weight-bearing surface (eg, bottom of the feet).

Common warts are sharply demarcated, rough, round or irregular, firm, and light gray, yellow, brown, or gray-black nodules 2 to 10 mm in diameter. They appear most often on sites subject to trauma (eg, fingers, elbows, knees, face) but may spread elsewhere. Variants of unusual shape (eg, pedunculated or resembling a cauliflower) appear most frequently on the head and neck, especially the scalp and beard area.

These warts are caused by HPV types 1, 2, and 4. They occur on the palms and soles.

Palmar and plantar warts are flattened by pressure and surrounded by cornified epithelium. They are often tender, and plantar warts can make walking and standing uncomfortable. They can be distinguished from corns and calluses by their tendency to pinpoint bleeding when the surface is pared away.

Flat warts are caused by HPV types 3 and 10 and occasionally 26 to 29 and 41. They are more common among children and young adults and develop by autoinoculation.

These warts are smooth, flat-topped, yellow-brown, pink, or skin-colored papules, most often located on the face and along scratch marks.

They generally cause no symptoms but are usually difficult to treat.

These warts are long, narrow, frondlike growths, usually located on the eyelids, face, neck, or lips. They are usually asymptomatic.

This morphologically distinct variant of the common wart is benign and easy to treat.

Periungual warts are caused by HPV types 1, 2, 4, and 7.

These warts appear as thickened, fissured, cauliflower-like skin around the nail plate. They are usually asymptomatic, but the fissures cause pain as the warts enlarge. Patients frequently lose the cuticle and are susceptible to paronychia.

Periungual warts are more common among patients who bite their nails or who have occupations where their hands are chronically wet such as dishwashers and bartenders.

Genital warts are caused by HPV type 6 or 11 (most commonly) and by types 1a, 2, 4, 7, 16, 18, 27b, 27, 33, 38, 40, 42, 43, 44, 54, 57b, 57c, 61, 72, 81, and 89 (1).

These warts manifest as discrete flat to broad-based smooth to velvety papules to rough and pedunculated excrescences on the perineal, perirectal, labial, and penile areas. They are usually asymptomatic, but perirectal warts often itch.

Infection with high-risk HPV types (most notably types 16 and 18 but also types 31, 33, 35, and 39) is the main cause of cervical cancer.

1. 1. Al-Awadhi R, Al-Mutairi N, Albatineh AN, Chehadeh W: Association of HPV genotypes with external anogenital warts: A cross sectional study. BMC Infect Dis 19(1):375, 2019. doi: 10.1186/s12879-019-4005-4

In immunocompetent patients, common warts usually spontaneously regress within 2 to 4 years, but some linger for many years. Numerous treatments are available. Destructive methods include electrocautery, cryosurgery with liquid nitrogen, and laser surgery. Salicylic acid preparations are also commonly used.

Which method is used depends on the location and severity of involvement.

podophyllum is removed in 2 hours. The longer these agents are left in contact with the skin, the more brisk the blistering response.

Cryosurgery is painful but extremely effective. Electrodesiccation with curettage, laser surgery, or both is effective and indicated for isolated lesions but may cause scarring.

Recurrent or new warts occur in about 35% of patients within 1 year; therefore, methods that scar should be avoided as much as possible so that multiple scars do not accumulate. When possible, scarring treatments are reserved for cosmetically unimportant areas and recalcitrant warts.

Treatment of filiform warts is removal with scalpel, scissors, curettage, or liquid nitrogen. Liquid nitrogen should be applied so that up to 2 mm of skin surrounding the wart turns white. Damage to the skin occurs when the skin thaws, which usually takes 10 to 20 seconds. Blisters can occur 24 to 48 hours after treatment with liquid nitrogen.

Care must be taken when treating cosmetically sensitive sites, such as the face and neck, because hypopigmentation or hyperpigmentation frequently occurs after treatment with liquid nitrogen. Patients with darkly pigmented skin can develop permanent depigmentation.

Treatment of flat warts is difficult, and flat warts are often longer-lasting than common warts, recalcitrant to treatments, and, in cosmetically important areas, make the most effective (destructive) methods less desirable.

Other destructive treatments (eg, CO2 laser, pulsed-dye laser, various acids) are often effective.

Using liquid nitrogen and cautery to treat periungual and lateral finger warts should be done carefully because overly aggressive treatment can cause permanent nail deformity and rarely nerve injury.

Several methods are available for the treatment of recalcitrant warts, but long-term value and risks are not fully known.

Raynaud syndrome or vascular damage may develop in injected digits, especially when the solution is injected at the base of the digit, so caution is warranted.

Intralesional injection of Candida antigen has also been reported to be moderately effective for recalcitrant warts.

Interferon, especially interferon alfa, given intralesionally (3 times/week for 3 to 5 weeks) or intramuscularly, has also cleared recalcitrant skin and genital warts.

The 9-valent HPV vaccine has been reported as useful for recalcitrant warts in children, but efficacy of this intervention is not proved (2).

1. 1. MuseME,Stiff KM,Glines KR, et al: A review of intralesional wart therapy. Dermatol Online J 26(3):13030/qt3md9z8gj, 2020.

2. 2. KostY,ZhuTH,Blasiak RC: Clearance of recalcitrant warts in a pediatric patient following administration of the nine-valent human papillomavirus vaccine. Pediatr Dermatol37(4):748–749, 2020.doi: 10.1111/pde.14150