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 specifically by HPV types 6 and 11, which are classified as low-risk, non-oncogenic types. 1, 2, 3
The remaining 10% of genital warts are caused by other HPV types, including occasionally high-risk types (16,18,31,33, and 35), though these are found much less frequently in visible warts. 1, 2
Important Clinical Distinctions
While all genital warts are HPV-caused, patients can be infected with multiple HPV types simultaneously, meaning someone with visible warts from types 6 or 11 may also harbor high-risk oncogenic types. 1, 2
High-Risk HPV Types in Genital Warts
HPV types 16,18,31,33, and 35 are occasionally found in visible genital warts and are strongly associated with squamous intraepithelial neoplasia and potential progression to squamous cell carcinoma of external genitalia. 1, 2
These high-risk types are more commonly associated with cervical dysplasia and anogenital cancers rather than visible warts. 1
Anatomical Distribution
Genital warts can occur at multiple sites beyond just external genitalia:
- External genitalia, perineum, and perianal skin 2
- Uterine cervix, vagina, urethra, and anus 1, 2
- Intra-anal warts occur predominantly in those with receptive anal intercourse history, while perianal warts can occur without such history 1, 2
Clinical Pitfall to Avoid
Do not assume that visible genital warts indicate only low-risk HPV infection. Biopsy should be performed when: 2
- Diagnosis is uncertain
- Lesions don't respond to standard therapy or worsen during treatment
- Patient is immunocompromised
- Warts are pigmented, indurated, fixed, or ulcerated
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