Genital warts (HPV)

Genital Warts (HPV)

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Key Point: Genital warts are caused by human papillomavirus (HPV), most commonly types 6 and 11 (low-risk, non-oncogenic). They are the most common viral STI in Australia. Treatment eliminates visible warts but does not eradicate HPV; recurrence is common. The national HPV vaccination program has dramatically reduced genital wart incidence in Australia.

Introduction & Australian Epidemiology

Genital warts (condylomata acuminata) are caused by HPV, predominantly types 6 and 11, which account for approximately 90% of cases. High-risk oncogenic types (HPV 16, 18) cause cervical, oropharyngeal, anal, vulvar, vaginal, and penile cancers but do not typically cause visible warts.

Australia introduced the school-based HPV vaccination program in 2007 for girls and 2013 for boys. The program uses the nonavalent vaccine (Gardasil®9, covering HPV 6, 11, 16, 18, 31, 33, 45, 52, 58) and has achieved one of the highest vaccination coverage rates globally. Genital wart notifications have fallen by over 90% in young heterosexual Australians since the program’s introduction, reflecting herd immunity effects.

Despite program success, genital warts remain prevalent among unvaccinated individuals, older age groups, men who have sex with men (MSM), and immunocompromised persons. HPV is transmitted via direct skin-to-skin contact during sexual activity; condoms reduce but do not eliminate transmission risk.

Pathophysiology & Virology

HPV is a non-enveloped double-stranded DNA virus of the Papillomaviridae family. Over 200 HPV types have been identified; genital tract infections are caused by ~40 mucosal types classified as low-risk or high-risk based on oncogenic potential.

Low-risk HPV (6, 11): Cause benign condylomata acuminata (genital warts) and recurrent respiratory papillomatosis. No malignant transformation.
High-risk HPV (16, 18, 31, 33, 45): Integrated into host genome, produce E6/E7 oncoproteins that inactivate p53 and Rb tumour suppressors, leading to dysplasia and carcinoma. Not associated with visible warts.

After infection, HPV establishes latency in basal epithelial cells. Incubation period for visible warts is typically 3 weeks to 8 months (average 2–3 months). Most HPV infections are cleared by the immune system within 1–2 years; persistent high-risk infection drives malignant transformation.

Clinical Presentation & Diagnostic Criteria

Clinical Features

Genital warts are diagnosed clinically. Biopsy is rarely needed but may be indicated in atypical, pigmented, or treatment-refractory lesions to exclude intraepithelial neoplasia or malignancy.

Morphology: Soft, flesh-coloured, skin-coloured or pink papules or plaques. May be flat, papular, pedunculated, or cauliflower-like (acuminata). Typically non-tender; may itch or bleed with trauma.
Male sites: Glans, foreskin, penile shaft, scrotum, perianal region, and intrameatal. Urethral warts may cause altered urinary stream.
Female sites: Vulva (labia minora/majora, fourchette), vagina, cervix, perianal region, and perineum. Cervical warts are flat and often subclinical.
Anal/rectal: Common in MSM; perianal warts visible externally; internal warts require anoscopy.
Oral/oropharyngeal: Less common; associated with oral–genital contact.

Differential Diagnosis

Molluscum contagiosum: Pearly, umbilicated papules — different morphology.
Condylomata lata (syphilis): Moist, flat plaques — test RPR/syphilis serology.
Pearly penile papules / Fordyce spots: Normal anatomical variants — circumferential rows on glans corona.
Vestibular papillomatosis: Symmetrical fine projections on inner labia minora — normal variant.
VIN / AIN / Bowen’s disease: Consider in pigmented, indurated, or atypical lesions — biopsy required.

Investigations

Genital warts are a clinical diagnosis. Investigations are directed at identifying co-existing STIs and assessing cervical/anal cancer risk.

Essential

Full STI Screen

Syphilis serology (RPR + TPPA), HIV Ag/Ab combination assay, gonorrhoea/chlamydia NAAT (first-void urine or urethral/cervical/rectal swabs), hepatitis B serology. All patients presenting with genital warts require concurrent STI screening.
Essential

Cervical Screening (females)

HPV-based cervical screening (Cervical Screening Test) as per Australian National Cervical Screening Program — 5-yearly from age 25 in women with a cervix, or earlier if symptomatic. Genital warts do not independently increase cervical cancer risk (low-risk HPV types), but concurrent high-risk HPV co-infection is possible.
Available

Anoscopy

Indicated in MSM and HIV-positive individuals with perianal warts or anal symptoms, to detect intraanal warts and anal intraepithelial neoplasia (AIN). High-resolution anoscopy (HRA) for AIN surveillance at specialist centres.
Available

Biopsy

Indicated if: atypical or pigmented lesions, failure to respond to standard therapy after 3 months, lesion ulceration, bleeding, or induration. Histopathology confirms HPV-related changes (koilocytosis) and excludes dysplasia/malignancy.
Available

HPV Genotyping

Not routinely indicated for genital warts (clinical diagnosis). May be performed on cervical/anal specimens as part of cancer screening pathways. Genotyping of wart lesions does not alter management.

Clinical Assessment & Treatment Selection

Treatment choice depends on wart morphology, size, number, location, and patient preference. No single treatment is superior for all wart types. All treatments have recurrence rates of 20–50% within 3 months due to viral latency in surrounding tissue.

PATIENT-APPLIED

Home Therapy

Imiquimod 5%, podophyllotoxin 0.5% solution or 0.15% cream. Suitable for external, accessible, non-keratinised warts. Patient must be able to identify and apply to lesions accurately.

Preferred where feasible — patient autonomy, clinic convenience

CLINICIAN-APPLIED

In-Clinic Therapy

Cryotherapy (liquid nitrogen), trichloroacetic acid (TCA) 80–90%, surgical excision, laser, or electrocautery. Required for large, keratinised, intraurethral, vaginal, cervical, anal, or oral warts.

Sexual health clinic, dermatology, gynaecology, or urology

SPECIALIST REFERRAL

Complex/Refractory

Warts unresponsive after 3 cycles of therapy, extensive/confluent lesions, giant condylomata (Buschke-Löwenstein tumour), immunocompromised patients with recalcitrant disease, or suspected malignant transformation.

Specialist sexual health, dermatology, colorectal surgery, gynaecology-oncology

Treatment — Patient-Applied Therapies

Patient-applied therapies are preferred for external genital warts that are accessible, well-demarcated, and not hyperkeratotic. Patients should be counselled on correct application technique before commencing home therapy.

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Imiquimod 5% Cream

Aldara® · Immune response modifier · First-line patient-applied

Application Apply thin layer to warts; rub in; leave overnight (6–10 hours); wash off with soap and water

Frequency 3 nights per week (e.g. Mon/Wed/Fri) for up to 16 weeks

Duration Up to 16 weeks; reassess at 8 weeks — discontinue if no improvement

Mechanism Toll-like receptor 7 agonist — induces local innate and adaptive immune response against HPV-infected cells

Adverse effects Local erythema, erosion, ulceration, pruritus — expected inflammatory response confirms immune activation. Reduce frequency if severe

PBS Status ⚠️ PBS Authority — condylomata acuminata

Pregnancy Contraindicated — use clinician-applied therapy (cryotherapy/TCA) instead

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Podophyllotoxin 0.5% Solution / 0.15% Cream

Wartec® · Antimitotic · First-line patient-applied

Application Solution: apply with cotton tip applicator to wart surface only; cream: apply fingertip; allow to dry

Frequency Twice daily for 3 consecutive days, then 4 days rest — repeat cycle for up to 4 cycles (5 weeks)

Duration Maximum 4 treatment cycles (5 weeks); maximum 0.5 mL per day (solution)

Mechanism Arrests cell division in metaphase by binding tubulin — direct cytotoxic effect on HPV-infected proliferating cells

Adverse effects Local burning, erosion, pain. Systemic toxicity if excessive area treated (rare)

PBS Status ✓ PBS Listed

Pregnancy Contraindicated — teratogenic and fetotoxic

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Sinecatechins 10% Ointment

Veregen® · Green tea extract · Second-line patient-applied

Application Pea-sized amount to each wart three times daily; do not wash off between applications

Duration Up to 16 weeks; continue until complete clearance

Availability Available in Australia via specialist prescription; not PBS-listed

PBS Status ✗ Not PBS listed

Treatment — Clinician-Applied Therapies

Cryotherapy (Liquid Nitrogen)

Cryotherapy with liquid nitrogen is the most widely used clinician-applied treatment. It is safe in pregnancy, effective for most wart types, and can be used on internal sites.

Technique: Apply liquid nitrogen with cryoprobe or cotton-tipped applicator until a 1–2 mm freeze halo develops around the wart. Allow to thaw completely before repeating (double freeze–thaw technique improves efficacy).
Frequency: Repeat every 1–3 weeks; typically 3–6 sessions required for clearance.
Suitable sites: External genitalia, perianal, vaginal, urethral meatus, anal canal.
Adverse effects: Burning pain during application, blistering, hypopigmentation (especially darker skin tones).

Trichloroacetic Acid (TCA) 80–90%

TCA is a chemical cauterant suitable for small, moist warts. It is safe in pregnancy and can be used on vaginal and cervical warts. Apply with a wooden stick to each wart, allow to dry (white frosting), and neutralise with sodium bicarbonate if excess applied. Repeat weekly.

Surgical & Ablative Therapies

Scissor excision / tangential shave: Quick, effective for pedunculated or large warts; provides tissue for histology. Local anaesthetic required.
Electrocautery / electrosurgical loop: Effective for large or extensive warts; smoke evacuation essential (infectious HPV in plume). Avoid in patients with pacemakers.
CO₂ laser: Precise ablation; preferred for extensive disease, intraurethral, or intraanal warts. Requires specialist operator.
Photodynamic therapy (PDT): Off-label; may be considered for extensive or refractory disease at specialist centres.

Monitoring Parameters

At Diagnosis

Confirm clinical diagnosis; perform full STI screen; document wart distribution, number, and size; assess vaccination history; counsel on transmission and recurrence; initiate treatment and provide written information.

2–4 Weeks

Review patient-applied therapy: assess response, confirm correct application technique, evaluate local adverse effects. Adjust frequency if severe local reactions. Clinician-applied therapy: second treatment session.

6–8 Weeks

Reassess treatment response. If no significant reduction in wart burden after 2 cycles of patient-applied therapy, switch to clinician-applied therapy or alternative agent. Document any new lesions.

12 Weeks

Complete clearance assessment. If warts persist after three treatment cycles, consider biopsy to exclude dysplasia and referral to specialist sexual health or dermatology. Reinforce STI screening.

Post-Clearance

Advise that HPV persists; recurrence rate 20–50% within 3 months of treatment. No further routine follow-up required after confirmed clearance in immunocompetent patients. Cervical/anal cancer screening per national guidelines.

Special Populations

🤰 Pregnancy

Warts may enlarge significantly during pregnancy. Patient-applied cytotoxic agents (podophyllotoxin, imiquimod, sinecatechins) are contraindicated. Vertical transmission causing laryngeal papillomatosis in infants is uncommon but possible.

Safe treatments: Cryotherapy (liquid nitrogen) and TCA 80–90% are safe throughout pregnancy and are the preferred modalities.
Timing of delivery: Caesarean section is not routinely recommended solely for genital warts unless obstruction of the birth canal is anticipated.
Neonatal risk: Recurrent respiratory papillomatosis (RRP) from HPV 6/11 vertical transmission is rare; estimated incidence 1 in 1500–2000 deliveries.
Vaccination: HPV vaccination is not recommended during pregnancy; defer until post-partum.

👶 Paediatrics

Genital warts in children require careful consideration of the mode of transmission. Perinatal transmission from maternal HPV is possible; however, sexual abuse must be considered and appropriately investigated.

Safeguarding: All children with anogenital warts require referral to a paediatrician for assessment and child protection evaluation.
Treatment: Cryotherapy is preferred. Imiquimod has limited data in children but may be used under specialist guidance.
Vaccination: HPV vaccine (Gardasil®9) is part of the national school immunisation program — offered free at age 12–13 years.

🛡️ Immunocompromised

HIV-positive individuals, transplant recipients, and others on immunosuppressive therapy have higher rates of HPV acquisition, larger and more extensive warts, poorer treatment response, and significantly elevated risk of HPV-related anal, cervical, and oropharyngeal cancers.

Treatment: Same modalities apply; however, higher recurrence rates and more sessions required. Combination approaches (e.g. cryotherapy + imiquimod) may be considered.
ART optimisation in HIV: Optimising antiretroviral therapy and immune reconstitution (CD4 count) improves HPV clearance and treatment response.
Cancer surveillance: Annual anal cytology or HRA for HIV-positive MSM with anal HPV exposure. Colposcopy referral if abnormal cervical screening.
Vaccination: HPV vaccination is recommended for HIV-positive individuals up to age 45 years; efficacy is reduced but still beneficial with higher CD4 counts.

🏥 MSM & Higher-Risk Groups

Men who have sex with men (MSM) carry a disproportionate burden of HPV-related disease, particularly anal warts and anal intraepithelial neoplasia, due to higher rates of anal intercourse and HPV exposure to multiple sites.

Anal screening: MSM presenting with perianal warts should have anoscopy to detect intraanal warts and AIN. Refer for HRA if AIN suspected.
Multi-site infection: Check penile, perianal, and urethral sites. Oral examination if history of oral–anal or oral–genital contact.
Vaccination catch-up: Unvaccinated MSM up to age 26 receive free HPV vaccine under the national program; vaccination up to age 45 is clinically beneficial for unvaccinated individuals.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander peoples face additional barriers to HPV vaccination, STI screening, and sexual health care. HPV vaccination coverage has improved but remains lower in remote communities than in urban settings. Co-existing STIs, particularly syphilis (active multi-jurisdictional outbreak) and chlamydia, are highly prevalent and must be actively screened for at every presentation.

Vaccination Coverage

HPV vaccination coverage in remote and very remote communities remains below national targets. School-based programs face access challenges. Community-based catch-up programs and outreach vaccination through primary health care networks should be actively promoted.

Access to Treatment

Cryotherapy and clinician-applied therapies require trained staff and liquid nitrogen supply, which may be unavailable in remote primary health care settings. Patient-applied therapies (podophyllotoxin, imiquimod with PBS authority) are more feasible but require adherence support and patient education in language.

Cultural Safety & Stigma

Sexual health consultations must be conducted by culturally safe, same-gender practitioners where possible. Use of interpreters and Aboriginal Health Workers facilitates disclosure. Plain language, translated resources, and non-judgmental communication improve engagement.

Concurrent STI Screening

Given high background STI prevalence, comprehensive STI screening (syphilis, HIV, gonorrhoea, chlamydia, hepatitis B) is mandatory at any sexual health presentation. Integrate genital warts management into broader sexual health check.

Antibiotic Stewardship (ACSQHC NSQHS Standard 3)

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No antibiotics required: Genital warts are caused by HPV — a virus. Antimicrobial agents have no role in treatment unless a concurrent bacterial STI (e.g. syphilis, gonorrhoea, chlamydia) is confirmed.

Avoid unnecessary antimicrobials: Secondary bacterial infection of treated warts is uncommon. Topical antiseptics are not routinely needed post-treatment.
Treat co-infections appropriately: If STI co-infection is detected on screening, treat per current Australian STI Management Guidelines (ASHM).
Prevention over treatment: HPV vaccination is the most effective stewardship tool — preventing infection eliminates the need for repeated treatment cycles and cancer surveillance interventions.

Follow-Up, Prevention & Partner Notification

HPV Vaccination

The nonavalent HPV vaccine (Gardasil®9) protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58. It is most effective when administered before sexual debut but still provides benefit to sexually active individuals not previously exposed to covered HPV types.

National program (free): 12–13-year-olds (school-based); MSM up to age 26 at sexual health clinics; Aboriginal and Torres Strait Islander peoples up to age 19.
Catch-up vaccination: Recommended for all unvaccinated individuals up to age 26. Clinically beneficial up to age 45 for those without prior HPV exposure to vaccine-covered types.
Dosing schedule: 2-dose schedule (0 and 6 months) for immunocompetent individuals <15 years; 3-dose schedule (0, 2, 6 months) for age ≥15 years or immunocompromised.
Post-wart diagnosis: Vaccination is still recommended even after diagnosis of warts — may protect against other HPV types not yet acquired.

Partner Notification

Partner notification for genital warts is recommended but not mandatory (unlike notifiable STIs). Partners within the past 6–12 months should be informed so they can seek STI screening and vaccination counselling. Contact tracing is primarily the responsibility of the patient; sexual health services can assist.

Transmission Reduction

Condom use: Reduces HPV transmission by approximately 70% but does not provide complete protection due to HPV shedding from areas not covered by condoms.
Abstinence during treatment: Patients should abstain from sexual activity or use condoms until warts are fully cleared to reduce transmission risk.
Cervical/anal screening: Ensure partners are up to date with cervical screening (females) and anal cancer surveillance (MSM, HIV-positive).

References

1Australasian Sexual Health Alliance (ASHA). Australian STI Management Guidelines for Use in Primary Care — Genital Warts. 2023. Available at: https://sti.guidelines.org.au
2Garland SM, Steben M, Sings HL, 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.
3Giuliano AR, Palefsky JM, Goldstone S, et al. Efficacy of quadrivalent HPV vaccine against HPV infection and disease in males. N Engl J Med. 2011;364(5):401–411.
4Australian Government Department of Health. National Immunisation Program — HPV Vaccine. Canberra: DoH; updated 2023. Available at: https://www.health.gov.au
5Palefsky JM, Giuliano AR, Goldstone S, et al. HPV vaccine against anal HPV infection and anal intraepithelial neoplasia. N Engl J Med. 2011;365(17):1576–1585.
6Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1–187.
7Chow EPF, Machalek DA, Tabrizi SN, et al. Quadrivalent vaccine-targeted human papillomavirus genotypes in heterosexual men in Melbourne, Australia. J Infect Dis. 2017;215(10):1598–1605.
8Garland SM, Kjaer SK, Muñoz N, et al. Impact and effectiveness of the quadrivalent HPV vaccine: a systematic review of 10 years of real-world experience. Clin Infect Dis. 2016;63(4):519–527.
9Cancer Council Australia Cervical Cancer Guidelines Working Party. National Cervical Screening Program Guidelines for the Management of Screen-Detected Abnormalities, Screening in Specific Populations and Investigation of Possible Cervical Cancer. Sydney: Cancer Council Australia; 2022.
10Kirby Institute. HIV, viral hepatitis and sexually transmissible infections in Australia: Annual Surveillance Report 2023. Sydney: Kirby Institute, UNSW Sydney; 2023.
11Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook — Human papillomavirus (HPV). Canberra: Australian Government Department of Health; 2023.
12Wiley DJ, Douglas J, Beutner K, et al. External genital warts: diagnosis, treatment, and prevention. Clin Infect Dis. 2002;35(Suppl 2):S210–S224.