dermatologic disorders
Warts
Treatment of Warts
Topical irritants (eg,salicylic acid,cantharidin,podophyllumresin) Destructive methods (eg, cryosurgery, electrocautery, curettage, excision, laser) Other topical therapies, intralesional injection therapies, or combinations There are no firm indications for treatment of warts. Treatment should be considered for warts that are cosmetically unacceptable, in locations that interfere with function, or painful. Patients should be motivated to adhere to treatment, which may require a prolonged course and can be unsuccessful. Treatments are less successful in patients with immunocompromise. Mechanisms of many irritants include eliciting an immune response to HPV. Such irritants includesalicylic acid(SCA),trichloroacetic acid, 5-fluorouracil,podophyllumresin (eg,podofilox),tretinoin, andcantharidin.Sinecatechinscan be used for genital warts. Topicalimiquimod5% cream induces skin cells to locally produce antiviral cytokines. Topicalcidofovirand contact immunotherapy (eg, squaric acid dibutyl ester andCandidaantigen) have been used to treat warts. Warts can first be soaked in hot water at 113° F for 30 minutes ≥ 3 times/week. After soaking, the skin is more permeable to topical agents.Candidaantigen can also be injected directly into the lesions. Oral treatments includecimetidine(which has questionable efficacy),isotretinoin, and zinc. IVcidofovircan also be used. In most instances, modalities should be combined to increase the likelihood of success. Direct antiviral effects can be achieved with intralesional injection ofbleomycinandinterferon alfa-2b, but these treatments are reserved for the most recalcitrant warts. These drugs can be used in combination with a destructive method (eg, cryosurgery, electrocautery, curettage, excision, laser) because even though a wart may be physically removed by a destructive method, virus may remain in the tissues and cause recurrence. Intralesional injections can be used to treat warts that are refractory, multiple, or in sensitive areas ( Treatment references ). For treatment of anogenital warts, see also Treatment . 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 acidpreparations are also commonly used. Which method is used depends on the location and severity of involvement. Salicylic acid(SCA) is the most common topical agent used. SCA is available as a liquid or plaster or impregnated within tape. For example, SCA 17% liquid can be used on the fingers, and SCA 40% plaster can be used on the soles. Patients apply SCA to their warts at night and leave it on for 8 to 48 hours depending on the site. SCA may be occluded with tape to enhance penetration. SCA may be compounded with 5-fluorouracilin various formulations for treatment of common warts on the palms and soles. Cantharidin(0.7% on thin-skinned areas and 1% on thicker-skinned areas) can be used alone or in combination with SCA 30% andpodophyllum5% in a collodion base.Cantharidinalone is removed with soap and water after 6 hours;cantharidinwith SCA orpodophyllumis 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. Usual first-line treatment is dailytretinoin(retinoic acid 0.05% cream). If peeling is not sufficient for wart removal, another irritant (eg, 5%benzoyl peroxide) or 5% SCA cream can be applied sequentially withtretinoin.Imiquimod5% cream can be used alone or in combination with topical agents or destructive measures. Topical 5-fluorouracil1% or 5% cream can also be used. Treatment of plantar warts is vigorous maceration with 40% SCA plaster kept in place for several days. The combination of 17% SCA and 2.5% 5-fluorouracilunder tape occlusion for 8 to 12 hours is also effective. The wart is then debrided while damp and soft, followed by destruction by freezing or using caustics (eg, 30 to 70%trichloroacetic acid). Other destructive treatments (eg, CO2 laser, pulsed-dye laser, various acids) are often effective. Combination therapy with liquid nitrogen andimiquimod5% cream,tretinoin, or SCA is effective and usually safer than liquid nitrogen alone or cautery. 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. Take care when treating periungual and lateral finger warts because aggressive liquid nitrogen and cautery 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. in saline often cures stubborn plantar and periungual warts. However, 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 ofCandidaantigen 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. Extensive warts sometimes abate or clear with oralisotretinoinoracitretin. The 9-valent HPV vaccine has been reported as useful for recalcitrant warts in children, but efficacy of this intervention is not proved ( Treatment references ). 1.Muse ME, Stiff KM, Glines KR, et al: A review of intralesional wart therapy.Dermatol Online J26(3):13030/qt3md9z8gj, 2020. 2.Kost Y, Zhu TH, 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 