Anogenital Warts

Introduction | Aetiology and Risk Factors | Clinical Presentation | Diagnosis | Management and Treatment | Prevention | When to Refer | References

Introduction

Anogenital warts, also known as condylomata acuminata, are a common sexually transmitted infection (STI) caused by certain types of human papillomavirus (HPV). These warts appear on the genital and anal areas, and less commonly, they may also affect the surrounding skin. Anogenital warts are typically benign, but certain strains of HPV are associated with an increased risk of malignancy, particularly in the cervix, anus, and oropharynx. They can cause significant psychological distress and may require treatment to reduce symptoms and transmission risk.

Aetiology and Risk Factors

Anogenital warts are caused by the human papillomavirus (HPV), specifically low-risk types, most commonly HPV 6 and 11. Key risk factors include:

• Sexual Activity: Transmission of HPV occurs through sexual contact, including vaginal, anal, and oral sex. Multiple sexual partners and early onset of sexual activity increase the risk.
• Immunosuppression: Individuals with weakened immune systems, such as those with HIV or those on immunosuppressive medications, are at higher risk of developing anogenital warts.
• Smoking: Smoking has been associated with an increased risk of HPV infection and the persistence of warts.
• Unprotected Sex: Not using condoms or other barrier methods increases the risk of HPV transmission.
• HPV Vaccination Status: Lack of vaccination against HPV increases the risk of infection with the strains that cause anogenital warts.

Clinical Presentation

Anogenital warts present with the following features:

• Appearance: Warts are typically small, flesh-coloured or grey, and may be flat, raised, or pedunculated (on a stalk). They often have a cauliflower-like appearance.
• Location: Warts can occur on the vulva, penis, scrotum, perineum, perianal area, and inside the vagina or anus. They may also appear on the surrounding skin.
• Symptoms: Warts are usually asymptomatic but may cause itching, discomfort, or bleeding, especially if irritated.
• Number and Size: The number and size of warts can vary, ranging from a single small lesion to multiple larger lesions.
• Subclinical Lesions: Some HPV infections cause flat lesions that are not visible to the naked eye but can be detected using acetic acid application or colposcopy.

Diagnosis

The diagnosis of anogenital warts is primarily clinical, based on the characteristic appearance of the lesions:

• History: Take a detailed sexual history, including the onset of symptoms, sexual partners, and any previous STIs or HPV-related conditions.
• Physical Examination: Examine the genital, perianal, and surrounding areas for the presence of warts. A speculum examination may be necessary to assess for warts inside the vagina or cervix.
• Acetic Acid Test: Applying acetic acid to the suspected area may turn the warts white, helping to visualise subclinical lesions, although this test is not specific for HPV.
• Biopsy: A biopsy may be performed if the diagnosis is uncertain, the lesions are atypical, or there is concern for malignancy (e.g., rapid growth, ulceration, or pigmentation).
• Screening for Other STIs: Given the sexually transmitted nature of HPV, screening for other STIs, including HIV, chlamydia, and gonorrhoea, is recommended.

Management and Treatment

Management of anogenital warts involves both medical and procedural treatments aimed at removing visible warts, reducing symptoms, and preventing transmission:

1. Topical Treatments

• Podophyllotoxin: A cytotoxic agent that can be self-applied to external warts. It works by destroying wart tissue. Treatment is usually applied twice daily for three days, followed by a four-day break, and repeated for up to four cycles.
• Imiquimod: An immune response modifier that stimulates the body's immune system to attack the HPV-infected cells. It is applied three times a week for up to 16 weeks.
• Trichloroacetic Acid (TCA): TCA is a chemical that destroys wart tissue by coagulating proteins. It is typically applied by a healthcare professional and may require multiple applications.

2. Procedural Treatments

• Cryotherapy: Freezing the warts with liquid nitrogen is a common and effective treatment. Multiple sessions are often required, spaced several weeks apart.
• Electrosurgery: This method uses an electric current to burn off warts. It is typically used for larger or more resistant warts and may require local anaesthesia.
• Surgical Excision: In cases where warts are extensive or resistant to other treatments, surgical removal under local or general anaesthesia may be performed.
• Laser Therapy: Laser treatment can be used to vaporise warts, particularly those in difficult-to-treat areas, such as the cervix or anus.

3. Supportive Care and Patient Education

• Patient Counselling: Educate patients about the nature of HPV, the potential for recurrence, and the importance of informing sexual partners. Discuss the psychological impact and offer support as needed.
• Condom Use: Advise the use of condoms to reduce the risk of HPV transmission, although they do not provide complete protection since warts may be present on areas not covered by a condom.
• Regular Follow-Up: Arrange follow-up appointments to monitor the response to treatment and manage any recurrences. Patients should be advised that warts may recur after treatment.

Prevention

Prevention of anogenital warts primarily involves vaccination and safe sexual practices:

• HPV Vaccination: The HPV vaccine (e.g., Gardasil) is highly effective in preventing infection with the most common wart-causing strains of HPV (6 and 11), as well as high-risk strains associated with cancer. The vaccine is recommended for both males and females, ideally before the onset of sexual activity.
• Safe Sexual Practices: Encouraging the use of condoms and limiting the number of sexual partners can reduce the risk of HPV transmission.

When to Refer

Ideally you should refer every patient to the sexual health clinic.

References

1. British Association for Sexual Health and HIV (BASHH) (2024) Guidelines for the Management of Anogenital Warts. Available at: https://www.bashh.org (Accessed: 26 August 2024).
2. National Institute for Health and Care Excellence (2024) Anogenital Warts: Diagnosis and Management. Available at: https://www.nice.org.uk/guidance/ng105 (Accessed: 26 August 2024).
3. British National Formulary (2024) Topical and Procedural Treatments for Dermatological Conditions. Available at: https://bnf.nice.org.uk/ (Accessed: 26 August 2024).
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