Intralesional Wart Treatments Are Among Options to Consider

SAN DIEGO — When Jennifer Adams, MD, recently entered the search term “warts” on the ClinicalTrials.gov web site, nearly 240 results popped up.

“There is a lot of research activity around this topic,” Dr Adams, vice chair of the department of dermatology at the University of Nebraska Medical Center, said at the annual meeting of the American Academy of Dermatology. “We just don’t have fantastic, well-run trials on many of the currently available treatments.”

In a 2012 Cochrane review on the topical treatment of non-genital cutaneous warts, authors drew from 85 trials involving 8815 randomized patients. They found that most warts spontaneously resolved, and the authors determined salicylic acid to be safe and modestly beneficial. Specifically, trials of salicylic acid (SA) vs placebo showed that the former significantly increased the chance of clearance of warts at all sites (risk ratio, 1.56; 95% confidence interval [CI], 1.20-2.03). A meta-analysis of cryotherapy vs placebo for warts at all sites favored neither intervention nor control (RR, 1.45; 95% CI, 0.65-3.23).

“The authors determined that there is less evidence for cryotherapy but stated that it may work when salicylic acid does not, or in combination with salicylic acid,” Dr Adams said. “However, salicylic acid and cryotherapy don’t do enough for our patients [with warts]. There are a lot of situations where we need to reach further into the toolbox.”

A 2021 review article listed many options for managing difficult-to-treat warts, including intralesional Candida antigen, intralesional measles-mumps-rubella (MMR), intralesional HPV vaccine, intralesional vitamin D, intralesional cidofovir, intralesional bleomycin, and intralesional 5-FU injections, and topical vitamin D, topical cidofovir, and topical bleomycin. According to Dr Adams, clinical data exist for cidofovir and vitamin D, but studies evaluated different formulations, doses, sites of administration, and limited randomized controlled trials.

“Intralesional cidofovir is more effective than the topical form, but intralesional cidofovir can be painful and both forms are expensive,” she said. “Topical vitamin D is less likely to cause dyspigmentation compared to other available treatments, so it’s a great option in skin of color, but it has been less effective compared to some of our other topical treatments.”

Newer Options Promising

On the horizon, berdazimer gel was approved in January of 2024 for the treatment of molluscum, but results from trials of its use for extragenital warts are encouraging. Another promising option is topical ionic contraviral therapy (ICVT) with digoxin and furosemide combined, which inhibits cellular potassium influx. A phase 2a randomized controlled trial of 80 adults found a statistically significant reduction in the diameter of cutaneous warts among those who received ICVT compared with those who received placebo (P = .002). “It’s cheap and well tolerated,” Dr Adams added.

Intralesional approaches to treating warts offer another alternative. A 2020 review of 43 articles concluded that intralesional treatments for warts have equal or superior efficacy to first-line salicylic acid or cryotherapy.

Dr Adams said that she considers intralesional treatments such as vitamin D, MMR vaccine antigen, and Candida antigen for refractory, numerous, or distant site warts. “Injecting the MMR vaccine into the largest wart every 2 weeks has been found to lead to complete clearance in 60%-68% of cases in one study,” she said. “The benefit is that it’s $21 per dose, which is nice, but as with any vaccination, patients can develop flu-like symptoms as side effects.”

Use of the HPV vaccine for treating cutaneous warts remains controversial, she continued, but it seems to work better in younger patients. In one open-label study that evaluated the HPV vaccine for the treatment of multiple recalcitrant warts, with doses administered at 0. 2 and 6 months, the response rate 3 months after the third dose was 55% among those older than age 26 compared with 84% among those ages 9-26 years.

Another option, intralesional cidofovir, has been shown to be especially effective for refractory warts. “It has also been shown to work for warts in immunocompetent and immunocompromised patients,” Dr Adams said.

In the realm of adjuvant treatments, microneedling has been found to have similar efficacy to needling, Dr Adams said, but with minimal pain. “When we combine it with topical treatments like 5-FU, it’s even more efficacious,” she said.

One study found that combining microneedling with topical 5-FU had clearance similar to that of intralesional 5-FU or microneedling alone but involved fewer treatment sessions and less pain in the combination group.

Autoinoculation has been used to stimulate an immune response in patients with warts, leading to clearance rates of 4% (mild clearance) to 66% (complete clearance) in one study. “We would expect this to work better in immunocompetent patients, but it’s something to keep in mind if you’re limited in the medications you can get for a patient,” Dr Adams said. Also, results from a systematic review and meta-analysis suggest that systemic retinoids combined with intralesional immunotherapy leads to higher clearance rates and lower rates of recurrence of warts. The top performer among those tested was acitretin plus Candida antigen.

Dr Adams advised dermatologists who try alternatives to salicylic acid and cryotherapy for warts to be “wary of a lack of high-level evidence” for their use. “They can be helpful for patients who have failed traditional therapies or have a contraindication to the usual go-tos.”

She reported having no relevant financial disclosures.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.