Genital warts are on the rise in women, particularly those over 40, prompting a new recommendation for prevention and treatment from the American College of Obstetricians and Gynecologists and the American Society for Colposcopy and Cervical Pathology.

The number of women with genital warts, or vulvar intraepithelial neoplasia  has quadrupled since the ’70s, the groups said – a rise thought to stem from increased exposure to the human papilloma virus. The virus, known as HPV, is the same sexually transmitted disease that causes cancers of the cervix, penis, anus and throat. And although  most genital warts are benign, some can progress to vulvar cancer.

“Although VIN appears to be increasing in the U.S., the risk of vulvar cancer is small when compared with cervical, ovarian, and uterine cancers,” Dr. L. Stewart Massad, a member of the ACO Committee on Gynecologic Practice, said in a statement about the recommendations scheduled for release Nov. 1. “VIN is similar to precancerous cervical lesions in that they are both generally slow-growing.”

The slow-growing nature of VIN is the reason women older than 40 have a higher incidence, although young women can develop VIN too, Massad said.

The only way to diagnose VIN is by visually examining the warts. Massad said women should use a hand mirror to check the area for unusual spots and make an appointment with a gynecologist if they see any changes.

Like precancerous cervical lesions caused by HPV, VIN can be treated with surgery or laser ablation to reduce the risk of cancer. But even with treatment, VIN can recur. Massad said women diagnosed with VIN should go for check-ups at six-month or one-year intervals.

The HPV vaccine used to prevent cervical cancer also helps prevent VIN, but won’t help treat it in women already infected with HPV.