Genital Warts

Genital warts, also known as condylomata acuminata, venereal warts, anal warts, or anogenital warts, are a sexually transmitted infection caused by certain types of human papillomavirus (HPV). They can present as small bumps in the genital area with varying sizes and shapes, typically protruding from the skin. Their colour may range from brownish, white, pale yellow, pinkish-red, to grey. While they usually cause few symptoms, they can be itchy, cause a burning sensation, and occasionally be painful. The onset of warts typically occurs one to eight months following exposure.

Signs and Symptoms

Genital warts can be found anywhere in the anal or genital area, including external surfaces like the penile shaft, scrotum, or labia majora, and internal surfaces like the opening to the urethra, inside the vagina, on the cervix, or in the anus. They can vary in size from 1–5 mm in diameter, but can also grow into large masses. Warts may be hard or soft and can bleed. Most HPV infections are asymptomatic, but warts may cause itching, redness, or discomfort, especially around the anus. Psychological distress, such as anxiety, may also occur.

Causes

Genital warts are primarily caused by HPV types 6 and 11, with occasional involvement of HPV types 16, 18, 31, 33, and 35. The virus is spread through direct skin-to-skin contact during oral, manual, vaginal, or anal sex. Condoms may reduce transmission, but are not always effective, especially for low-risk HPV variants.

Latency and Recurrence

HPV infections often clear within two years, but the virus can remain latent and recur. Latent HPV is still transmissible, and new warts may arise from either new exposure or recurrence of a previous infection. About one-third of individuals with warts experience recurrence.

Transmission in Children

Children can acquire genital warts during birth or through non-sexual means such as autoinoculation from warts elsewhere on the body, sharing of personal items, or routine care like diapering. In children, genital warts are less likely to be caused by HPV subtypes 6 and 11.

Diagnosis

Diagnosis is typically visual but may be confirmed by biopsy. Genital warts have distinct histopathological features, including enlargement of the dermal papillae and characteristic nuclear changes. DNA tests are available for high-risk HPV but not for low-risk types causing warts. The use of acetic acid for identifying subclinical lesions is controversial and not recommended by UK guidelines.

Prevention

Gardasil, a vaccine protecting against HPV types 6, 11, 16, and 18, is effective in preventing genital warts and cervical cancer. It is preventive and ideally administered before sexual activity begins. Cervarix, effective against HPV types 16 and 18, was replaced by Gardasil in the UK.

Treatment

There is no cure for HPV, and treatments focus on removing visible warts, which may regress on their own. Treatments include physical ablation and topical agents, each with varying efficacy and potential side effects.

Physical Ablation

Physically ablative methods, such as simple excision, cryosurgery, electrocauterisation, laser ablation, and formal surgical procedures, are effective but may cause scarring and other side effects.

Topical Agents

Topical treatments include podophyllotoxin, imiquimod, sinecatechins, and trichloroacetic acid. These agents vary in effectiveness and side effects, with some like podophyllotoxin and imiquimod being more commonly used. Discontinued treatments include 5% 5-fluorouracil cream due to side effects.

Oral Agents

Oral isotretinoin has shown efficacy in treating recalcitrant condylomata acuminata of the cervix.

Epidemiology

Genital HPV infections have a high prevalence, with clinical manifestations in 1% of the sexually active adult population in the US. Although treatments can remove warts, recurrences are common, and the virus can be cleared or suppressed by the immune system to undetectable levels.

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Self-assessment MCQs (single best answer)

What causes genital warts?

Which HPV types are primarily responsible for genital warts?

What is the typical incubation period for genital warts after exposure to HPV?

Which vaccine is effective in preventing genital warts and cervical cancer?

What is one common symptom that genital warts can cause?

What is the primary method of diagnosing genital warts?

Which of the following is not a recommended physical ablation method for treating genital warts?

Which topical agent has been discontinued due to side effects for treating genital warts?

What percentage of sexually active adults in the US is estimated to have clinical manifestations of genital HPV infections?

Which of the following statements is correct about HPV infections?