What Human Papillomavirus (HPV) variant is most commonly associated with warts?

HPV Variants Associated with Warts

HPV types 6 and 11 are the variants most commonly associated with genital warts, with HPV-6 being the most prevalent. 1

Epidemiology and Causative HPV Types

Human papillomavirus (HPV) infections are extremely common, with more than 30 types capable of infecting the genital tract. However, the distribution of HPV types varies significantly based on the clinical manifestation:

• Genital Warts:

  • Approximately 90% of all genital warts are caused by HPV types 6 and 11 1
  • HPV-6 is the most frequently detected type in genital warts, with a prevalence of about 13% in males and being the second most common type in females 2
  • HPV-11 is the other major low-risk type associated with warts

• High-Risk Types:

  • HPV types 16,18,31,33, and 35 are occasionally found in visible genital warts but are more strongly associated with cervical dysplasia and other anogenital cancers 1
  • These high-risk types can be present in warts but are not the primary causative agents of typical warts

Clinical Manifestations

HPV types 6 and 11 can cause warts in multiple anatomical locations:

• External genitalia (penis, vulva, scrotum, perineum)
• Uterine cervix
• Vagina
• Urethra
• Anus
• Non-genital sites including conjunctival, nasal, oral, and laryngeal warts 1

Genital warts caused by HPV-6 and HPV-11 may be:

• Painful
• Friable (easily bleeding)
• Pruritic (itchy)
• Asymptomatic in many cases 1

Molecular Variants and Risk

Recent research has shown that specific molecular variants within HPV-6 may influence the development of genital warts:

• HPV-6 B1 variants are more prevalent in genital swabs that precede genital wart development and confer an increased risk for wart formation 3
• The distribution of HPV-6 variants differs between countries and case status 3

Important Clinical Considerations

1. Co-infection: Patients with visible genital warts can be simultaneously infected with multiple HPV types, including both low-risk and high-risk types 1, 4

2. Pregnancy: Genital warts can proliferate during pregnancy due to altered immunity and increased blood supply 5

3. Treatment challenges: While warts can be treated with various modalities (cryotherapy, electrocautery, laser therapy, etc.), the HPV virus cannot be completely eliminated 6

4. Recurrence: Recurrence of anogenital warts is common (approximately 30%), whether clearance occurs spontaneously or following treatment 1

Conclusion

When evaluating a patient with warts, clinicians should recognize that HPV-6 and HPV-11 are the predominant causative types, with HPV-6 being the most common. However, testing for specific HPV types is not routinely recommended for the diagnosis or management of visible genital warts 1.