Anogenital warts guide: Risk factors and clinical manifestations

This guide focuses on the assessment and management of external anogenital warts (AGW) caused by human papillomaviruses (HPV). HPV vaccination and HPV-related cancer screening recommendations are beyond the scope of this guide.

Risk factors

Risk factors for anogenital warts (AGW) include:

not receiving HPV9 vaccines^{Footnote 1}^{Footnote 2}^{Footnote 3}^{Footnote 4}
younger age at initiation of sexual activity (sexual debut)^{Footnote 5}^{Footnote 6}^{Footnote 7}
sexual activity without barrier protection (condom, dental dam)^{Footnote 8}^{Footnote 9}^{Footnote 10}^{Footnote 11}^{Footnote 12}
new^{Footnote 4}^{Footnote 5}^{Footnote 7} or multiple sexual partners^{Footnote 4}^{Footnote 7}^{Footnote 12}
higher number of lifetime sexual partners^{Footnote 4}^{Footnote 6}^{Footnote 7}^{Footnote 10}^{Footnote 13}^{Footnote 14}^{Footnote 15}^{Footnote 16}
history of STBBI^{Footnote 4}^{Footnote 6}^{Footnote 15}^{Footnote 17}^{Footnote 18}
smoking^{Footnote 4}^{Footnote 6}^{Footnote 10}^{Footnote 15}^{Footnote 18}^{Footnote 19}^{Footnote 20}^{Footnote 21}
immunosuppression (innate or acquired), including HIV infection^{Footnote 4}^{Footnote 6}^{Footnote 15}^{Footnote 22}^{Footnote 23}^{Footnote 24}.

The lifetime occurrence of AGW has been found to be higher among gay, bisexual and other men who have sex with men (gbMSM) and women who have sex with women (WSW)^{Footnote 4}.

Transmission

HPV types 6 and 11 are transmitted predominantly by epithelial contact. Transmission can occur during oral, vaginal and anal sex^{Footnote 6}^{Footnote 11}^{Footnote 18}^{Footnote 22}^{Footnote 25} and other intimate skin-to-skin contact^{Footnote 6}^{Footnote 11}.

Perinatal transmission of HPV types 6 and 11 is possible^{Footnote 11}^{Footnote 18}^{Footnote 25}^{Footnote 26}^{Footnote 27}^{Footnote 28}.

HPV 6 and 11 are transmissible in the absence of lesions^{Footnote 29}. Treatment may reduce the risk of transmission, but likely does not eliminate it^{Footnote 28}.

Clinical manifestations

The incubation period for anogenital warts (AGW) varies from 3 weeks to 8 months^{Footnote 6}^{Footnote 11}^{Footnote 18}^{Footnote 30}. The majority of AGW spontaneously regress. Approximately 30% of AGW regress within 4 months^{Footnote 18}, and more than 90% regress within 24 months^{Footnote 6}^{Footnote 29}. Winer et al. found that the median time to clearance of AGW with treatment was 5.9 months^{Footnote 30}.

Recurrence of AGW is common, including after treatment^{Footnote 11}^{Footnote 18}^{Footnote 28}.

A diagnosis of AGW can have significant psychosocial consequences^{Footnote 4}^{Footnote 11}^{Footnote 15}^{Footnote 17}^{Footnote 28}^{Footnote 31}^{Footnote 32}, including:

fear of recurrence, transmission, and developing cancer^{Footnote 32}^{Footnote 33} and
depression, sexual dysfunction, and disruption of sexual relationships^{Footnote 33}.

Signs and symptoms

HPV 6 and 11 infections are often asymptomatic or sub-clinical^{Footnote 11}^{Footnote 28}.

Anogenital warts present as individual or (more commonly) multiple asymmetrical, polymorphic, exophytic fronds or growths on anogenital skin and mucous membranes^{Footnote 11}^{Footnote 18}^{Footnote 28}. AGW:

can be flesh-coloured, brown or pink
can vary in appearance from papular to cauliflower-like
can fluctuate in size and number and
can spontaneously regress and resolve^{Footnote 11}^{Footnote 18}^{Footnote 28}^{Footnote 34}.

AGW can occasionally cause pruritus, local discharge, and bleeding^{Footnote 11}^{Footnote 28}.

During pregnancy, AGW may recur, expand or become friable, and are often less responsive to treatment^{Footnote 28}^{Footnote 34}.

The risk of developing AGW is higher among people who are immunocompromised and among people living with HIV^{Footnote 28}. For these individuals, AGW may be more numerous and larger^{Footnote 28}. AGW may also recur more frequently and be recalcitrant to treatment^{Footnote 28}.

References

Footnote 1

Drolet M, Bénard É, Pérez N, Brisson M, Ali H, Boily M-C, et al. Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis. Lancet 2019;394(10197):497-509.

Return to footnote 1 referrer

Footnote 2

Righolt CH, Willows K, Kliewer EV, Mahmud SM. Incidence of anogenital warts after the introduction of the quadrivalent HPV vaccine program in Manitoba, Canada. PLoS ONE 2022;17(4):e0267646.

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Footnote 3

Steben M, Tan Thompson M, Rodier C, Mallette N, Racovitan V, DeAngelis F, et al. A Review of the Impact and Effectiveness of the Quadrivalent Human Papillomavirus Vaccine: 10 Years of Clinical Experience in Canada. J Obstet Gynaecol Can 2018;40(12):1635-1645.

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Footnote 4

Tyros G, Mastraftsi S, Gregoriou S, Nicolaidou E. Incidence of anogenital warts: epidemiological risk factors and real-life impact of human papillomavirus vaccination. Int J STD AIDS 2021;32(1):4-13.

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Footnote 5

Burchell AN, Tellier P-, Hanley J, Coutlée F, Franco EL. Human papillomavirus infections among couples in new sexual relationships. Epidemiology 2010;21(1):31-37.

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Footnote 6

Forcier M, Musacchio N. An overview of human papillomavirus infection for the dermatologist: Disease, diagnosis, management, and prevention. Dermatol Ther 2010;23(5):458-476.

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Footnote 7

Garland SM, Steben M, Sings HL, James M, Lu S, Railkar R, et al. Natural history of genital warts: Analysis of the placebo arm of 2 randomized phase III trials of a quadrivalent human papillomavirus (types 6, 11, 16, and 18) Vaccine. J Infect Dis 2009;199(6):805-814.

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Footnote 8

Nielson CM, Harris RB, Nyitray AG, Dunne EF, Stone KM, Giuliano AR. Consistent condom use is associated with lower prevalence of human papillomavirus infection in men. J Infect Dis 2010;202(3):445-451.

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Footnote 9

Pierce Campbell CM, Lin H-Y, Fulp W, Papenfuss MR, Salmerón JJ, Quiterio MM, et al. Consistent condom use reduces the genital human papillomavirus burden among high-risk men: The HPV infection in men study. J Infect Dis 2013;208(3):373-384.

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Footnote 10

Wen LM, Estcourt CS, Simpson JM, Mindel A. Risk factors for the acquisition of genital warts: Are condoms protective? Sex Transm Infect 1999;75(5):312-316.

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Footnote 11

Steben M, Garland SM. Genital warts. Best Pract Res Clin Obstet Gynaecol 2014;28(7):1063-1073.

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Footnote 12

Winer RL, Hughes JP, Feng Q, O'Reilly S, Kiviat NB, Holmes KK, et al. Condom use and the risk of genital human papillomavirus infection in young women. New Engl J Med 2006;354(25):2645-2654.

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Footnote 13

Aubin F, Prétet J-L, Jacquard A-C, Saunier M, Carcopino X, Jaroud F, et al. Human papillomavirus genotype distribution in external acuminata condylomata: A large French national study (EDiTH IV). Clin Infect Dis 2008;47(5):610-615.

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Footnote 14

Dunne EF, Unger ER, Sternberg M, McQuillan G, Swan DC, Patel SS, et al. Prevalence of HPV infection among females in the United States. J Am Med Assoc 2007;297(8):813-819.

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Footnote 15

Trottier H, Franco EL. The epidemiology of genital human papillomavirus infection. Vaccine 2006;24(SUPPL. 1):S4.

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Footnote 16

Vriend HJ, Boot HJ, Van Der Sande MAB. Type-specific human papillomavirus infections among young heterosexual male and female STI clinic attendees. Sex Transm Dis 2012;39(1):72-78.

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Footnote 17

Chelimo C, Wouldes TA, Cameron LD, Elwood JM. Risk factors for and prevention of human papillomaviruses (HPV), genital warts and cervical cancer. J Infect 2013;66(3):207-217.

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Footnote 18

Yanofsky VR, Patel RV, Goldenberg G. Genital warts: A comprehensive review. J Clin Aesthetic Dermatol 2012;5(6):25-36.

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Footnote 19

Hansen BT, Hagerup-Jenssen M, Kjær SK, Munk C, Tryggvadottir L, Sparén P, et al. Association between smoking and genital warts: Longitudinal analysis. Sex Transm Infect 2010;86(4):258-262.

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Footnote 20

Kaderli R, Schnüriger B, Brügger LE. The impact of smoking on HPV infection and the development of anogenital warts. Int J Colorectal Dis 2014;29(8):899-908.

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Footnote 21

Vaccarella S, Herrero R, Snijders PJF, Dai M, Thomas JO, Hieu NT, et al. Smoking and human papillomavirus infection: Pooled analysis of the International Agency for Research on Cancer HPV Prevalence Surveys. Int J Epidemiol 2008;37(3):536-546.

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Footnote 22

International Agency for Research on Cancer Working Group. Human papillomaviruses (HPV). IARC Monographs 2007;90.

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Footnote 23

Machalek DA, Poynten M, Jin F, Fairley CK, Farnsworth A, Garland SM, et al. Anal human papillomavirus infection and associated neoplastic lesions in men who have sex with men: A systematic review and meta-analysis. Lancet Oncol 2012;13(5):487-500.

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Footnote 24

Van Aar F, Mooij SH, Van Der Sande MAB, Speksnijder AGCL, Stolte IG, Meijer CJLM, et al. Anal and penile high-risk human papillomavirus prevalence in HIV-negative and HIV-infected MSM. AIDS 2013;27(18):2921-2931.

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Footnote 25

Hahn HS, Kee MK, Kim HJ, Kim MY, Kang YS, Park JS, et al. Distribution of maternal and infant human papillomavirus: Risk factors associated with vertical transmission. Eur J Obstet Gynecol Reprod Biol 2013;169(2):202-206.

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Footnote 26

Freitas AC, Mariz FC, Silva MAR, Jesus ALS. Human papillomavirus vertical transmission: Review of current data. Clin Infect Dis 2013;56(10):1451-1456.

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Footnote 27

Park H, Lee SW, Lee IH, Ryu HM, Cho AR, Kang YS, et al. Rate of vertical transmission of human papillomavirus from mothers to infants: relationship between infection rate and mode of delivery. Virology journal 2012;9(1):80.

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Footnote 28

Workowski KA, Bachmann LH, Chan PA, Johnston CM, Muzny CA, Park I, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep 2021 07 23;70(4):1-187.

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Footnote 29

Brianti P, De Flammineis E, Mercuri SR. Review of HPV-related diseases and cancers. The new microbiologica 2017;40(2):80-85.

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Footnote 30

Winer RL, Kiviat NB, Hughes JP, Adam DE, Lee S-, Kuypers JM, et al. Development and duration of human papillomavirus lesions, after initial infection. J Infect Dis 2005;191(5):731-738.

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Footnote 31

Karnes JB, Usatine RP. Management of external genital warts. Am Fam Phys 2014;90(5):312-318.

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Footnote 32

Maw RD, Reitano M, Roy M. An international survey of patients with genital warts: Perceptions regarding treatment and impact on lifestyle. Int J STD AIDS 1998;9(10):571-578.

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Footnote 33

Clarke P, Ebel C, Catotti DN, Stewart S. The psychosocial impact of human papillomavirus infection: Implications for health care providers. Int J STD AIDS 1996;7(3):197-200.

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Footnote 34

O'Mahony C, Gomberg M, Skerlev M, Alraddadi A, de las Heras-Alonso ME, Majewski S, et al. Position statement for the diagnosis and management of anogenital warts. J Eur Acad Dermatol Venereol 2019;33(6):1006-1019.

Return to footnote 34 referrer

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Date modified:: 2024-02-09

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