Warts

EPIDEMIOLOGY

HPV Subtypes - Genital Warts

90% of genital warts (GW) are cause by HPV 6 and 11. Other GW HPV subtypes include 40, 42, 43, 44, 54, 61, 72, 81.

Natural History - Genital Warts

An analysis of HPV infection incidence and clearance by genotype and age in men: The HPV Infection in Men (HIM) Study. Papillomavirus Res. 2015. PMID: 27547836.

Objective: The study aimed to examine how often and how long men acquire and clear HPV infections, specifically by HPV type and age.
Methods: Over 4000 HIV-negative men aged 18–70, with no history of genial warts, from the U.S., Mexico, and Brazil were followed for a median of about 4 years. Genital samples (Dacron swabs) were collected every six months and tested for 37 HPV genotypes.
Results:
- HPV Acquisition:
  - Annual incidence of acquisition is pretty similar across age groups (not a big drop off as men get older).
  - The annual incidence of infection with the HPV types included in the 9-valent vaccine was around 13-17%, and decreased slightly (though not statistically significant) with age.
  - Annual incidence of acquiring a GW-associated HPV subtype is ~10-12% (my calculation based on adding up rates of different subtypes and adjusting downward to account for multiple infections).
  - Risk factors for acquiring: higher number of lifetime and recent (w/in 6 months) female sexual partners, higher number of male sex partners, uncircumcision, smoking.
HPV Clearance:
- About 50% clear HPV 6/11 within 1 year, 90% by 2 years. Data for other GW-subtypes is similar. High-risk subtypes take longer to clear.
Conclusions/Limitations:
- Men can acquire new HPV infections at any age.
- This study only looked at HPV acquisition and clearance based on presence of viral DNA. They assumed, I think prematurely, that rates of clearance of warts would follow rates of clearance of viral DNA, but in this was not studied. It is very possible that the presence of warts indicates impaired immunity, and as a result may also correlate with lower spontaneous clearance rates.

TREATMENT

Hyperthermia

Clearance of multiple cutaneous warts by targeting a single lesion: A randomized comparative evaluation of mild local hyperthermia versus cryotherapy. J Am Acad Dermatol. 2022. PMID: 35934211.

SUMMARY: RCT of local hyperthermia at 44C for 30 min, 3 consecutive days one week followed by 2 consecutive days two weeks later followed by weekly treatment for 2 sessions (7 total treatments) versus cryotherapy applied with a cotton tipped applicator 3 times in a month separated by 2 week intervals. Patients with multiple common warts, plantar warts, or condyloma acuminata were included. The same wart was treated at each session and the rate of clearance of other non-treated warts was observed. No difference in the rate of clearance of the treated wart was observed between hyperthermia and cryotherapy. 54.5% of the hyperthermia treated patients had complete wart clearance versus 27.2% of the cryotherapy treated patients (p<0.01). Pain was significantly worse in the cryo group. The difference could certainly be attributed to under-treatment of cryotherapy arm given modality of cryotherapy delivery chosen.

HPV Vaccination

Although the two studies below show evidence supporting the use of HPV vaccination for warts, systematic reviews have not shown convincing efficacy (need citations, and more comprehensive review. big distinction between IL HPV and HPV vaccination).

Nofal A, Nofal H, Alwirshiffani E, ElGhareeb MI. Treatment response and tolerability of intralesional quadrivalent versus bivalent human papillomavirus vaccine for recalcitrant warts: A randomized controlled trial. J Am Acad Dermatol. 2023. PMID: 37422014.

MY SUMMARY: 50 patients were randomized to IL quadrivalent (20), IL bivalent (20), and IL saline (10). 0.1ml was injected into a single wart (largest) every 2 weeks until clearance or up to 5 treatments. 18 of 20 in the quadrivalent group, 6 of 20 in the bivalent group, and 0 of 10 in the saline group experienced complete clearance.

The human papillomavirus vaccine as a treatment for human papillomavirus-related dysplastic and neoplastic conditions: A literature review. J Am Acad Dermatol. 2020. PMID: 31085272.

CONCLUSION: The commercially available three-dose, quadrivalent HPV vaccine is a potential therapeutic option for the treatment of cutaneous warts, recurrent respiratory papillomatosis, and squamous and basal cell carcinomas. Noncommercially available HPV vaccines demonstrate therapeutic response for treating anogenital warts, cervical intraepithelial neoplasia, anal intraepithelial neoplasia, and vulvar intraepithelial neoplasia. The vaccine’s efficacy as an adjunct therapy for HPV-associated cutaneous and/or mucosal disease warrants further exploration.

Intralesional versus intramuscular bivalent human papillomavirus vaccine in the treatment of recalcitrant common warts. J Am Acad Dermatol. 2020. PMID: 31369771.

CONCLUSION: Bivalent HPV vaccine, particularly by intralesional injection, seems to be a potential therapeutic option for the treatment of multiple recalcitrant common warts.

Home Remedies

Pinto Bean Pressure Wraps: A Novel Approach to Treating Digital Warts. Cutis. 2024. PMID: PMID: 39787310.

This article introduces a simple, low-cost home treatment for common digital warts using dried pinto beans as pressure applicators. It is a descriptive case-based narrative outlining the method. They provide only anecdotal observations stating that "most warts resolve with this technique" and recurrence is "similar to that for cryotherapy." The method involves taping a small, hard, convex object—preferably a pinto bean—over the wart and securing it with a self-adherent wrap overnight. The sustained pressure induces ischemia (restricted blood flow), which selectively damages wart tissue, allowing it to slough off within 1–2 weeks. The technique is described as nearly pain-free and has recurrence and response rates similar to conventional methods like cryotherapy.

Rationale: Warts contain tortuous blood vessels that are more susceptible to ischemia than normal skin.
Advantages: Low cost, no need for clinical visits, minimal discomfort, and minimal risk of scarring.
Effectiveness: Most warts resolve with one to three nightly applications. Recurrence rates are comparable to cryotherapy. This is claimed by the authors but they do not provide data regarding this.
Limitations: Ineffective on non-digital warts due to difficulty maintaining pressure. (May be Not suitable for patients with compromised circulation (e.g., Raynaud's, systemic sclerosis).
Safety: Caution against choking hazards and allergic reactions; beans must remain dry and should not be ingested.

Periungual/Subungual Warts

Treatment Pearls 39549844

Subungual and periungual warts are are difficult to treat, with high recurrence rates and potential for persistent infection. First-line treatment in adults is intralesional bleomycin, while topical therapies are preferred in children due to pain concerns. Immunocompromised patients require biopsy to rule out malignancy and may need a cautious, multimodal approach. Patients should be counseled that treatment often requires multiple sessions, outcomes can vary, and recurrence is common even after successful therapy.