Common warts - Emerging treatments | BMJ Best Practice US

Topical cidofovir

Can be used for especially recalcitrant lesions.[33] It is not approved by the Food and Drug Administration (FDA) for warts. Topical formulations of cidofovir need to be made by a compounding pharmacy.

Topical cantharidin

Produces a blister after application to the wart surface. This is more often used in children, but has the greatest chance of producing a doughnut wart.[34] Cantharidin is no longer available in the US. Subsequently, a phase 2 open-label clinical study has been conducted examining cantharidin 0.7% solution in a proprietary single-use applicator. The study showed complete clearance of all treatable warts, at day 84, in 51% of patients. In the remaining patients, a reduction in the number of treatable warts by 51% from baseline was observed. The treatment was well-tolerated and no serious adverse events were reported.[35]

Human papillomavirus (HPV) vaccine

Vaccination with the HPV vaccine has been reported to decrease warts in case reports; however, further investigation is required.[36][37][38]

Photodynamic therapy

Photodynamic therapy (PDT) is emerging as a safe and effective therapy for warts. A systematic review and meta-analysis of 19 randomized controlled trials found PDT resulted in low recurrence rates, minor adverse reactions, and positive clinical outcomes.[39] Used in conjunction with 20% topical aminolevulinic acid and a broad-band light source. Potentially complicated by significant pain, although this is typically reported to be milder and more acceptable compared to cryotherapy.[39][40][41]

Topical hydrogen peroxide solution

A phase 2 randomized, double-blind, vehicle-controlled trial of 45% hydrogen peroxide topical solution supported the efficacy and safety in the treatment of common warts in the ages of 8 years and up.[42] A phase 3, randomized, double-blind, vehicle-controlled trial of 45% hydrogen peroxide topical solution, reported significantly higher rates of clearance at day 60 in the treatment arm. Additionally, the secondary endpoints of complete clearance of all warts at day 137 and time to complete clearance were both significantly in favor of 45% hydrogen peroxide topical solution. The most common side effects (occurring in over 5% of participants) were application site pain, pallor, erythema, pruritus, scabbing and erosion.[43]

Intralesional measles, mumps and rubella (MMR) vaccine

An immunotherapeutic option with potential added benefits of encouraging regression of untreated distant lesions. Although the mechanism is not well understood, it is thought to stimulate a delayed-type hypersensitivity reaction against both the antigen and HPV, which then targets locally treated and untreated distant lesions.[44][45]

Intralesional purified protein derivative (PPD)

Intralesional PPD has been reported effective for recalcitrant warts in a randomized, placebo-controlled, double-blind clinical trial of 69 participants which, randomized patients between intralesional PPD and intralesional saline.[46] Another study on 30 patients found comparable efficacy and safety in treatment of multiple warts with intralesional PPD and MMR.[47]

Zinc supplementation

Oral zinc sulfate has been reported as an efficacious therapy for recalcitrant common warts; however, it is not a standard therapy.[48] Evidence has suggested that it may be effective in selected populations with zinc deficiency.[49]

Dinitrochlorobenzene

Dinitrochlorobenzene (DNCB) has been found to be more than twice as effective as placebo in two clinical trials; however, this drug is not widely available and may need to be compounded by a pharmacist.[10] Recent studies found higher efficacy with intralesional candida than with DNCB.[50]

Other treatments

Cimetidine, levamisole, and homeopathy have also been studied with inconsistent evidence on efficacy.[49] These treatments are not recommended. Various other treatments have been published with limited numbers of patients described, including Bacille Calmette-Guerin (BCG) vaccine, erbium-doped yttrium-aluminum-garnet (Er:Yag) laser, pulsed-dye laser, and topical fluorouracil.[51]