Are All Genital Warts Caused by HPV?
Yes, all anogenital warts (condyloma) are caused by HPV infection. 1
Specific HPV Types Responsible
Approximately 90% of genital warts are caused by HPV types 6 and 11, which are considered low-risk types. 1, 2
The remaining 10% of visible genital warts may be caused by other HPV types, including high-risk types 16,18,31,33, and 35, though these are found only occasionally in visible genital warts. 1, 2
Clinical Significance of HPV Type Distinction
HPV types 6 and 11 cause benign genital warts and are rarely associated with invasive squamous cell carcinoma of the external genitalia. 1
HPV types 16,18,31,33, and 35, when present in visible genital warts, are associated with external genital squamous intraepithelial neoplasia (including squamous cell carcinoma in situ, bowenoid papulosis, Erythroplasia of Queyrat, or Bowen's disease). 1, 2
Patients with visible genital warts can be infected simultaneously with multiple HPV types. 1
Important Clinical Caveats
Biopsy is indicated when the diagnosis is uncertain, lesions do not respond to standard therapy, disease worsens during therapy, the patient is immunocompromised, or warts are pigmented, indurated, fixed, and ulcerated—as these atypical features may suggest high-risk HPV types or malignancy. 1, 2
Type-specific HPV nucleic acid testing is not recommended for routine diagnosis or management of visible genital warts, as it does not change clinical management. 1, 2
The average time to development of new anogenital warts after infection with HPV types 6 or 11 is approximately 2-3 months, though not all persons infected with these types will develop visible warts. 1