Laser treatment is effective against nongenital cutaneous warts, based on data from a review of 35 studies comprising 2,149 adult patients.

“No monotherapy has achieved completed remission [of nongenital cutaneous warts] in every case,” wrote Jannett Nguyen, a medical student at the University of California, Irvine, and colleagues (JAMA Dermatol. 2016 April 27. doi: 10.1001/jamadermatol.2016.0826).

The researchers reviewed data on warts treated with one of four types of lasers: Carbon dioxide (CO2), erbium:yttrium-aluminum-garnet (Er:YAG), pulsed dye laser (PDL), or neodymium-doped yttrium aluminum garnet (Nd:YAG).

The response rates for the different lasers were 50%-100% for CO2, 72%-100% for Er:YAG, 31%-100% for PDL, and 46%-100% for Nd:YAG. The studies included data on laser treatment of several types of nongenital warts including simple and recalcitrant common warts, periungual and subungual warts, and palmoplantar warts.

In general, side effects from laser treatment of warts were highest with CO2 lasers, and included scarring, hypopigmentation, postoperative pain, and prolonged wound healing. PDL was associated with the lowest risk of side effects, and was as effective as conventional therapies, including cryotherapy and cantharidin.

In Er:YAG treatments, the laser was used for direct ablation of the epidermis on the wart, repeating through layers until normal skin is revealed. Overall, patients treated with Er:YAG demonstrated a higher response and lower recurrence when treated in combination with podofilox. Nd:YAG treatment was similar to PDL, but with a longer wavelength that allows for deeper penetration.

Treatment is limited by a lack of evidence to guide selection of the most appropriate lasers for different warts and by a lack of recommendations for specific laser settings, the researchers noted. Additional studies are needed to establish treatment protocols by comparing lasers to each other and to nonlaser treatments.

However, laser treatment of warts can be “an additional therapeutic option and the studies reviewed here can provide a starting point in determining settings,” they said.

The researchers had no financial disclosures.