Anogenital Warts

Anogenital warts are overwhelmingly caused by human papillomavirus (HPV) types 6 and 11. Diagnosis is usually clinical. No available treatment eradicates the underlying HPV infection itself, and no single treatment is proven superior to the others or ideal for every patient or every wart — treatment clears the visible lesions, and recurrence after apparently successful treatment is common. The 9-valent HPV vaccine prevents infection with the types that cause the great majority of anogenital warts and is a genuinely effective prevention strategy, distinct from treating warts once they occur.^[1]

• Skin-coloured, pink, or grey papules or plaques in the anogenital region, which can be flat, dome-shaped, or the classic cauliflower-like (verrucous) morphology.
• Can occur on the external genitalia, perianal area, or — less commonly and requiring specific attention — the cervix, vagina, urethral meatus, or anal canal.
• Usually asymptomatic, though larger lesions can cause itching, bleeding, or mechanical discomfort.

Diagnosis is usually made clinically without biopsy. Consider biopsy, and referral to a specialist, when the diagnosis is uncertain — this is particularly relevant for lesions on the cervix or in the anal canal, where the appearance is more often atypical. Refer any patient with warts on the cervix to a gynecologist. Internal anal lesions can often be managed with cryotherapy via anoscope; when this is not available, refer to a proctologist or surgeon.

• Sexual contact with a partner who has anogenital warts or HPV infection — the likelihood of transmission and duration of infectivity are not precisely known, but condom use is associated with decreased HPV transmission.
• Lack of HPV vaccination.
• Immunosuppression, which is associated with more extensive and treatment-resistant disease.

Diagnosis is clinical in the great majority of cases. Biopsy is reserved for diagnostic uncertainty, atypical-appearing lesions, or lesions in the cervix or anal canal where an unusual appearance is more likely to represent something other than a typical wart. Screen for other STIs when clinically indicated, since anogenital warts are a marker of sexual exposure like any other STI.

• Clear visible lesions.
• Relieve associated itching, bleeding, or discomfort.
• In pregnancy specifically, relieve symptoms only — see Special Populations.
• Reduce future risk through HPV vaccination where the patient has not already been vaccinated.

• Observation alone is appropriate for minimal, asymptomatic disease, since spontaneous resolution occurs in some patients.
• Offer the 9-valent HPV vaccine for future prevention (see Special Populations/Drug Tables) — this does not treat existing warts but prevents new infection with the vaccine-covered types.
• Counsel on condom use to reduce (though not eliminate) transmission risk to partners.
• Cryotherapy, laser therapy, and surgical excision are procedural options administered by a clinician experienced with the technique, useful for larger or treatment-resistant lesions.

HPV vaccination

Recommend the 9-valent HPV vaccine to every patient under 26 years of age, and consider the benefit on an individual basis for patients over 26. The vaccine is not recommended in pregnancy but can be used during breastfeeding.^[3]

• Reassess response at the treatment-specific interval (see Drug Tables) — most regimens are given for defined multi-week courses and should show a response within that window.
• Recurrence after apparent clearance is common even with effective treatment — counsel the patient about this in advance so it is not mistaken for treatment failure of a different kind.
• Reinforce that no treatment eradicates the underlying HPV infection, only the visible lesions.

1. Confirm the treatment was applied correctly and for the full recommended duration — patient-applied topical regimens are particularly prone to under-application.
2. Switch to an alternative treatment modality (patient-applied to office-based, or vice versa) rather than repeating an already-failed regimen unchanged.
3. Reconsider the diagnosis and biopsy if the lesion's appearance is atypical or has changed.
4. Refer to a specialist for extensive, treatment-resistant, or diagnostically uncertain disease.

• Using podophyllin on cervical, meatal, vaginal, or anal warts — it must not be used at these sites.
• Using podophyllin or imiquimod in a pregnant patient — both are contraindicated.
• Treating cervical warts without gynecology referral.
• Promising a patient that treatment will prevent recurrence — recurrence after apparently successful treatment is common and should be discussed up front.
• Not offering HPV vaccination because the patient already has warts — vaccination still protects against the other covered HPV types the patient has not yet acquired.

How to use this table: No therapy guarantees HPV eradication — these treatments clear visible lesions. Select any drug name to open its complete Pharmasist Drug Database page.

Topical Treatment of External Warts

Antimitotic Agents

Office-based only; not for cervical, meatal, vaginal, or anal warts.

Antivirals

Self-applied, botanical (green tea extract).

Caustic Agents

Office-based; the preferred option in pregnancy.

Immune Response Modifiers

Self-applied; first-line patient-applied option.

Vaccination for Prevention

Vaccines

Prevents new infection with the covered types — does not treat existing warts.

Evidence note: Drug inventory, dosing, adverse effects, and comments reflect standard Canadian practice per current PHAC guidance.^[1]