Genital warts result from infection with one of the more than 60 known strains of human papillomavirus. Transmitted by sexual contact, the virus incubates from 1 to 6 months (the average is 2 months) before warts erupt.

During pregnancy, genital warts in the vaginal and cervical walls may grow so large that they impede vaginal delivery. Other complications include possible genital tract dysplasia or cancer. (Studies have shown an association between human papillomavirus types 11, 16, and 18 and cervical dysplasia and cancer.)

The patient’s history may include unprotected sexual contact with a partner with a known infection, a new partner, or many partners.

Examination reveals warts growing on the moist genital surfaces, such as the subpreputial sac, the urethral meatus and, less commonly, the penile shaft or scrotum in male patients and the vulva and vaginal and cervical walls in female patients. In both sexes, papillomas spread to the perineum and the perianal area. Warts may begin as tiny red or pink swellings. These lesions may grow as large as 4° (10.2 cm) and may become pedunculated. Multiple swellings have a cauliflower-like appearance. Most patients report no symptoms; a few complain of pruritus or pain. Infected lesions become malodorous.

Dark-field microscopy of wart-cell scrapings shows marked epidermal cell vascularization. This differentiates genital warts from condylomata lata associated with second-stage syphilis.

Another test involves applying 5% acetic acid (white vinegar) to the warts, which will turn white if they’re papillomas.