At any point in time, around 1% of the US population is estimated to have anogenital warts.21 Overall, it has been estimated that 6% of US residents report a history of genital warts.1 Warts vary in appearance: most lesions are external and can be raised (i.e.,“cauliflower” formation) or flat, single or multiple, small or large. Typically, warts are asymptomatic but sometimes itch, bleed, or cause irritation.1 Warts can be found in multiple anogenital sites including the vulva, vagina, cervix (less common), penis (including under the foreskin in uncircumcised ales), scrotum, urethra, anus, and perineum.22 The groin and lower abdomen can be involved, but this is uncommon.
Visual inspection by an experienced clinician usually is sufficient for accurate diagnosis. However, biopsy sometimes is required if the visual diagnosis is uncertain or for lesions that are uncharacteristic in appearance (e.g., pigmented or ulcerated).22 The currently available HPV tests are not approved or recommended for diagnosis of warts. Application of acetic acid, which has been promoted as a diagnostic aid by highlighting the wart-involved tissues, is neither sensitive nor specific, and is not recommended.21
Treatment of Genital Warts
The goal of treatment is to eliminate warts. While it is possible that doing so helps prevent transmission by reducing the HPV viral load, this is speculative. No available therapy has been shown to cure HPV infection or reduce the risk of transmission, in part because the virus typically is also present in skin or mucosa that appears normal, without visible warts.
There are numerous therapeutic options for genital warts, including both provider- and patient-directed treatments. No single approach to treating warts is universally superior. The selection of a treatment option is influenced by factors that include size of warts, anatomic site, number and distribution of lesions, as well as provider and patient preferences.22 Warts eventually regress naturally, sometimes within a few months, so a “watchful waiting” approach occasionally is appropriate. Recurrences are not uncommon, especially in the first 3 months following therapy. With the exception of surgery or other forms of direct destruction or removal, all recommended treatments are only 60% to 80% effective in ablating warts, and none are more effective than others in preventing recurrence.1 When a particular treatment is not effective or if warts regrow within 3 months, a different modality should be used. Some experts routinely use combination therapy, such as initial cryotherapy followed by a patient-applied treatment.
Treatment regimens for genital warts are outlined below. Information is summarized from the Centers for Disease Control and Prevention (CDC) 2010 STD treatment guidelines, except where noted.22
Patient-Applied Prescription Treatments
- Podofilox (Condylox®): Podofilox is a purified derivative of podophyllin resin, and is available as a topical solution or gel.23 Podofilox is applied to genital warts twice a day for 3 days, followed by 4 days of no therapy. This cycle can be repeated up to 4 times. Podofilox use is contraindicated during pregnancy.
- Imiquimod (Zyclara® 3.75% cream or Aldara® 5% cream): Imiquimod is a topical immune response modifier. Zyclara is applied once daily for up to 8 weeks.24 Aldara can be used 3 times a week (i.e., every other night before bed) for up to 16 weeks. Patients should wash their hands after applying imiquimod, and the cream should be washed off approximately 8 hours after application.24 Imiquimod is substantially less effective against warts on dry surfaces than those on moist surfaces (e.g., the vulva or under the foreskin). Imiquimod has not been studied in pregnant women.24
- Sinecatechins (Veregen®): This extract from green tea is a recently approved treatment for genital warts. Available as an ointment, sinecatechins is applied to warts 3 times daily for as long as 16 weeks. Side effects include local irritation including rashes, itching, burning, and ulceration. Sinecatechins is contraindicated during pregnancy.
- Trichloroacetic acid (TCA) and bichloroacetic acid (BCA): Highly caustic acid compounds that are quite effective in rapidly ablating warts, but occasionally cause short but intense pain.1 Care must be taken to prevent contact with normal skin, and some providers protect the area around warts with petroleum jelly.25 Treatment can be repeated weekly, if necessary. Safe to use during pregnancy.23
- Cryotherapy: Freezing tissue (usually liquid nitrogen), which directly destroys wart tissue by thermal injury. After treatment, the outer layer of tissue forms a blister and separates from deeper layers. Cryotherapy is appropriate for both external and internal warts, and for lesions on the cervix. Although pain at the application site is common (and, occasionally, scarring occurs where the treatment was applied to the wart), cryotherapy is generally well tolerated.25
- Podophyllin resin: Efficacy of podophyllin may vary in part because of poor and variable concentrations of the active compounds.1 Podophyllin is applied directly to warts, allowed to dry, and the patient is instructed to wash the compound away after 1 to 4 hours; treatment typically is applied weekly. Podophyllin is limited to external use and is contraindicated during pregnancy.
- Surgery and related methods: For appropriately trained clinicians, direct surgical removal may be appropriate, especially for certain locations (e.g., intraurethral warts) or particularly large warts. Other related methods also requiring sophisticated training include laser therapy and electrocautery.