What are the treatment options for genital warts (Human Papillomavirus (HPV) infection) on the buttock?

Treatment Options for Genital Warts on the Buttock

For genital warts on the buttock, first-line treatment options include patient-applied therapies such as podofilox 0.5% solution or imiquimod 5% cream, or provider-administered treatments like cryotherapy with liquid nitrogen or trichloroacetic acid (TCA) 80-90%. 1

First-Line Treatment Options

Patient-Applied Therapies:

1. Podofilox 0.5% solution or gel

   • Application: Twice daily for 3 consecutive days, followed by 4 days without treatment
   • Treatment cycle can be repeated up to 4 times until warts clear
   • Efficacy: 45-88% clearance rate
   • Limitations: Contraindicated during pregnancy
   • Side effects: Mild to moderate pain or local irritation
   • Maximum treatment area: Less than 10 cm² of wart tissue and no more than 0.5 mL per day 2

2. Imiquimod 5% cream

   • Application: Three times weekly at bedtime for up to 16 weeks
   • Efficacy: Approximately 35% complete clearance in men with genital warts, 72% in women 3
   • Mechanism: Immune enhancer that stimulates production of interferon and cytokines
   • Limitations: Contraindicated during pregnancy
   • Side effects: Local inflammatory reactions including redness and irritation
   • Note: May weaken condoms and vaginal diaphragms 1

Provider-Administered Therapies:

1. Cryotherapy with liquid nitrogen

   • Application: Every 1-2 weeks as needed
   • Efficacy: 63-88% with recurrence rates of 21-39%
   • Advantages: Relatively inexpensive, does not require anesthesia
   • Disadvantages: Requires special equipment, patients experience moderate pain 4, 1

2. Trichloroacetic acid (TCA) or Bichloroacetic acid (BCA) 80-90%

   • Application: Weekly as needed
   • Technique: Apply until white "frosting" develops, neutralize excess with talc/sodium bicarbonate
   • Efficacy: 81% with recurrence rate of 36%
   • Particularly useful for moist surfaces or intertriginous areas 4, 1

Treatment Selection Algorithm

1. For small, few warts on dry surfaces of the buttock:

   • First choice: Podofilox 0.5% solution/gel
   • Alternative: Imiquimod 5% cream

2. For warts on moist areas of the buttock or intertriginous areas:

   • First choice: TCA/BCA 80-90% or imiquimod
   • Alternative: Provider-administered cryotherapy

3. For extensive warts on the buttock:

   • First choice: Provider-administered cryotherapy or surgical removal
   • Alternative: Combination of methods

Special Considerations

• Pregnancy: Podofilox and imiquimod are contraindicated; TCA/BCA or cryotherapy are preferred 1
• Immunosuppressed patients: May have lower response rates to imiquimod 1
• Recurrence: All treatments have recurrence rates of at least 25% within 3 months 1
• Treatment monitoring: Change treatment if no substantial improvement after three provider-administered treatments or if warts haven't cleared after six treatments 1

Important Caveats

1. Treatment removes warts but does not eradicate HPV infection 4
2. Spontaneous resolution occurs in 20-30% of cases within 3 months, making watchful waiting an acceptable alternative for some patients 4, 1
3. Scarring in the form of persistent hypopigmentation or hyperpigmentation is common with ablative modalities 1
4. Extensive or refractory disease should be referred to a specialist 4
5. Treatments that are expensive, toxic, or result in scarring should be avoided 4

Remember that the goal of treatment is clearance of visible warts to reduce symptoms and improve cosmetic appearance. No treatment has been proven to completely eradicate HPV infection or prevent transmission 4.