Dermatology MCQ - Viral Infections -
Ano-genital warts

A 25-year-old sexually active woman presents with multiple, flesh-colored, exophytic, cauliflower-like papules in the vulvar and perianal region. The lesions are asymptomatic but have been gradually increasing in size and number. She has no significant medical history and is otherwise healthy. Which of the following is the most appropriate first-line treatment and the oncogenic risk associated with the most common viral types causing this condition?

A) Topical imiquimod; low oncogenic risk
B) Surgical excision; high oncogenic risk
C) Cryotherapy; high oncogenic risk
D) Oral acyclovir; low oncogenic risk
E) Intralesional interferon; moderate oncogenic risk

Correct Answer: A) Topical imiquimod; low oncogenic risk

Explanation

This presentation is classic for ano-genital warts (condylomata acuminata), caused by specific types of human papillomavirus (HPV).

Key Clinical Features of Ano-Genital Warts:

• Appearance: Flesh-colored, pink, or hyperpigmented exophytic papules with a cauliflower-like (verrucous) surface.

• Location: Vulva, vagina, cervix, perianal area, penis, or scrotum.

• Transmission: Sexual contact (including oral, genital, or anal sex).

• Symptoms: Often asymptomatic, but can cause pruritus, discomfort, or bleeding.

Virologic Cause and Oncogenic Risk:

• Most Common Types: HPV types 6 and 11 (low-risk types) cause over 90% of ano-genital warts.

• Oncogenic Risk: These types are low-risk and are not associated with significant carcinogenic potential. They do not integrate into the host genome like high-risk types.

• High-Risk Types: HPV 16, 18, 31, 33, etc., are associated with cervical, anal, and oropharyngeal cancers but typically cause flat, subclinical lesions (not exophytic warts).

First-Line Treatment:

• Topical imiquimod (5% cream): An immune response modifier applied by the patient 3 times per week. It stimulates local cytokine production (e.g., interferon) to clear the virus. It is preferred for external warts due to its efficacy and self-application.

• Other Options:

  • Podophyllotoxin: Patient-applied cytotoxic agent.

  • Cryotherapy: Provider-applied freezing for limited disease.

  • Surgical methods: Excision, electrocautery, or laser for large or refractory warts.

Why Not the Other Options?

• (B) Surgical excision; high oncogenic risk: Excision is reserved for large or resistant warts but is not first-line. The viral types causing exophytic warts are low-risk.

• (C) Cryotherapy; high oncogenic risk: Cryotherapy is a first-line provider-applied treatment, but the oncogenic risk is low, not high.

• (D) Oral acyclovir; low oncogenic risk: Acyclovir is for herpesviruses, not HPV. It has no role in treating warts.

• (E) Intralesional interferon; moderate oncogenic risk: Interferon is used for refractory warts but is not first-line due to cost and side effects. The oncogenic risk is low.

Prevention:

• HPV vaccination (Gardasil 9): Protects against HPV 6, 11, 16, 18, and 5 other high-risk types. Recommended for adolescents and young adults.

• Barrier protection: Condoms reduce but do not eliminate transmission risk.

Prognosis:
Warts may regress spontaneously, recur, or persist. Treatment aims to remove visible warts and reduce symptoms, but does not eradicate the virus. Regular screening for cervical cancer (e.g., Pap smear) is recommended for women.