Q. I recently developed a wart on my hand. What can I do to get rid of it?
Warts are treatable, but which method is best?
A. Warts are caused by a virus. When the virus infects skin cells, they grow faster than normal. It's not clear why, but some people are more prone to warts than others.
Skin warts aren't highly contagious. But the virus that causes warts can spread from person to person by direct contact, and warts on one part of the body can spread to other areas. That's why it's important to wash your hands after touching a wart -- yours or someone else's, like your kids' warts.
Warts are generally harmless and often disappear on their own over time. It's not clear why some warts go away and other warts don't. One theory about those that go away is that the immune system responds to the viral infection that causes the warts. Another is that the virus just "poops out" and stops causing cells to grow faster than normal.
Some doctors think stress may bring out warts. The theory is that the virus that causes warts lives inside a person's skin cells quietly, not making trouble. When a person is under stress, the immune system does not do as good a job of keeping the virus in check. As a result, the wart starts to develop.
I have had patients with recurrent warts who swear that warts are more likely to appear when they are under stress. I think it's a plausible, but unproven, theory.
If you're not too bothered by their appearance, it's fine to just keep an eye on warts. They may just go away. On the other hand, promptly treating a wart should reduce the chances of it spreading to another part of your body.
Getting rid of warts can be a challenge, but there are several treatment options you can try:
• Salicylic acid: This is the main ingredient in aspirin, and it should usually be your first choice. Salicylic acid costs little and has minimal side effects. It comes in various over-the-counter preparations, including liquids, gels and patches.
To treat a wart, soak it for 10 to 15 minutes. File away the dead warty skin with an emery board or pumice stone and apply the salicylic acid. Do this once or twice a day for 12 weeks.
• Freezing (cryotherapy): A clinician swabs or sprays liquid nitrogen onto the wart and a small surrounding area. The extreme cold burns the skin, causing pain, redness and usually a blister. Getting rid of the wart this way usually takes three or four treatments, one every two to three weeks.
• Duct tape: Believe it or not, silver (not clear) duct tape may work, although studies have come to different conclusions about this. Place the duct tape over your wart for six days. Remove the tape, soak and file the wart, and leave it uncovered overnight. Reapply the duct tape in the morning and leave the tape in place for another six days. Follow this regimen for two months or until the wart disappears.
• Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: AskDoctorK.com.