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What are Genital warts?

Genital warts (GW) are one of the most common sexually transmitted diseases, and are caused by certain types of the human papillomavirus (HPV). They are characterized by visible skin lesions with either single or multiple small growths on the genitalia, including the vulva, perianal area, vagina, penis, anus, or scrotum.1 These growths can vary in color from pink, purple, red, or brown, and in appearance from flat to cauliflower-shaped lumps.2

In the U.S., an estimated 0.5-1 million new cases of genital warts occur annually and about half of these new cases occur in people between the ages of 15 and 24. Among sexually active people, about 1% have visible warts.2 Genital warts are more common in young females than young males.1

What are common symptoms?

About 6-10 months after being infected with HPV, you may develop physical symptoms. Genital warts often appear as multiple growths in moist areas of the genitalia. The growths can look flat, dome-shaped, or cauliflower-shaped. While they usually cause little discomfort or pain, the warts can get irritated after contact with clothing or during sexual intercourse, leading to occasional discomfort, burning sensations, and itchiness.2,3

What are the causes?

Sexually transmitted HPV can be classified into low-risk or high-risk types. Low-risk HPV (lrHPV) types – such as 6, 11, 42, and 44 – are associated with benign genital warts. High-risk HPV types (hrHPV) – such as 16 and 18 – can cause cervical cancer in females, and anal and throat cancers in both females and males.

HPV is transmitted via skin-to-skin contact. After infection, viral replication occurs in the deep cell layers of the skin. In some cases, the immune system is able to clear the HPV infection without any treatment. However, when the immune response fails, lrHPV replication produces benign growths in the skin.2,3,4

Risk factors for GW are (in order of relevancy)2,5:

  • Increased number of sexual partners
  • Use of oral contraceptives
  • History of sexually transmitted infections
  • Smoking
  • Weakened immune system

How does this condition relate to my microbiome?

Unlike the gut microbiota, a healthy vagina has low microbial diversity. Infection with lrHPV, the virus that causes genital warts, is related to higher microbial diversity and the presence of fewer beneficial microorganisms in the vagina, such as the Lactobacillus species.6 Additionally, HPV infection is more common among women with bacterial vaginosis (BV), whose vaginal microbiota often has increased levels of Sneathia species or Gardnerella vaginalis.6,7

Which diseases/topics are related to genital warts?

Gential warts are associated with BV and risk factors such as unprotected sex or multiple partners. These risk factors can also lead to other sexually transmitted diseases, such as8

  • Chlamydia
  • Gonorrhea
  • Hepatitis C
  • Herpes
  • Pelvic inflammatory disease
  • Syphilis
  • Trichomoniasis

How can people take action?

The best way to prevent lrHPV infection is abstinence, condom use, or having a monogamous relationship with a disease-free partner.8 The HPV vaccine is recommended by the Advisory Committee on Immunization Practices for females and males aged 11-26 years, and has recently been approved by the FDA for adults between 27-45.9 However, the vaccine only protects against certain hrHPV types, and does not include protection against any lrHPV types.10

If you suspect that you have GW, visit your healthcare provider for a diagnosis and treatment. Treatment can involve relieving symptoms and/or removal of the warts with cryotherapy, surgical excision, or topical treatment.2,8


1. Patel, H., Wagner, M., Singhal, P., & Kothari, S. (2013). Systematic review of the incidence and prevalence of genital warts. BMC Infectious Diseases, 13(1), 39.

2. Yanofsky, V. R., Patel, R. V, & Goldenberg, G. (2012). Genital warts: a comprehensive review. The Journal of Clinical and Aesthetic Dermatology, 5(6), 25–36.

3. Steben, M., & Garland, S. M. (2014). Genital warts. Best Practice and Research: Clinical Obstetrics and Gynaecology, 28(7), 1063–1073.

4. Stanley, M. A. (2012). Epithelial cell responses to infection with human papillomavirus. Clinical Microbiology Reviews, 25(2), 215–222.

5. Tobian, A. A. R., Serwadda, D., Quinn, T. C., Kigozi, G., Gravitt, P. E., Laeyendecker, O., … Gray, R. H. (2009). Male Circumcision for the Prevention of HSV-2 and HPV Infections and Syphilis. New England Journal of Medicine, 360(13), 1298–1309.

6. Mitra, A., MacIntyre, D. A., Marchesi, J. R., Lee, Y. S., Bennett, P. R., & Kyrgiou, M. (2016). The vaginal microbiota, human papillomavirus infection and cervical intraepithelial neoplasia: what do we know and where are we going next? Microbiome, 4(1), 58.

7. Kyrgiou, M., Mitra, A., & Moscicki, A.-B. (2017). Does the vaginal microbiota play a role in the development of cervical cancer? Translational Research, 179, 168–182.

8. Centers for Disease Control and Prevention (2015) 2015 Sexually Transmitted Diseases Treatment Guidelines.

9. U.S. Food & Drug Administration. FDA approves expanded use of Gardasil 9 to include individuals 27 through 45 years old (October 5, 2018).

10. Leiding, J. W., & Holland, S. M. (2012). Warts and all: Human papillomavirus in primary immunodeficiencies. Journal of Allergy and Clinical Immunology, 130(5), 1030–1048.