One old legend has it that you should dig up an onion under the full moon, cut it in half, and tie it to your foot at night to rid yourself of plantar warts, which develop on the soles of the feet. So far, there’s no evidence that technique works, although it’s one of several old-fashioned and somewhat amusing folk remedies.
Others say that you should put duct tape on the wart. That one really does work! A 2002 study found that covering the wart with duct tape for six days, then soaking the wart in water and rubbing it with a pumice stone, when repeated until the wart disappears, is an effective removal method. “I do sometimes recommend a topical wart medicine combined with the duct tape approach,” says Dr. Amy Balettie, a podiatrist with Foot Healers.
Balettie hypothesizes that the duct tape remedy is effective because the tape removes some of the top layers of callused skin cells, exposing the slightly deeper layer where the wart is more difficult to treat. There also may be some degree of antiviral activity triggered by the adhesive, although there is no clinical evidence to prove this theory.
“Plantar warts are very common,” says Dr. Michael Heffernan, a dermatologist with Central Dermatology in Clayton. “They are more common in teens and young adults, although I see them among all age groups.”
Warts are caused by one of the many strains of human papillomavirus (HPV), which thrives in warm, wet conditions. Subsequently, transmission often occurs in locker rooms, showers and public pool areas where the virus is left on surfaces and picked up by barefoot walkers who happen across the infected area.
“Some people who are exposed to the virus mount an immune response that prevents them from getting warts, so not everyone who comes in contact with the virus ends up with plantar warts,” notes Dr. John Holtzman, a podiatrist with Missouri Foot & Ankle. He recommends wearing shower shoes in locker rooms and around pools and drying the feet well before putting on socks or regular sandals.
If a wart does develop, over-the-counter treatments can be effective, although they may take longer than professional treatment by a podiatrist, dermatologist or primary-care physician. All treatments, whether at home or administered in a physician’s office, are topical, although the techniques and medications used vary. Left untreated, plantar warts can spread or become painful.
Another reason to seek medical attention is that some people mistake warts for calluses, fibromas (a mass of fibrous tissue), blisters or foreign bodies that have worked their way under the epidermis, Balettie says. However, she notes that it is unusual for a patient to develop more plantar warts following a successful course of therapy. In most cases, patients need a series of several treatments spaced over weeks or months, depending on the severity and number of warts being treated.
“In-office treatments destroy the wart with the application of liquid nitrogen, heat or laser,” says Heffernan. Acid preparations, similar to over-the-counter salicylic acid solutions, also are used by some physicians. In general, “we use the approach that will give us the best result with the least amount of damage. We prefer liquid nitrogen to laser treatments because there’s less scarring.”
So the next time you look out your window to gaze at the full moon and notice your neighbor digging up onions, you might toss him a roll of duct tape and suggest he make a doctor’s appointment. LN