Dr. Greene, my 10 year old has suddenly gotten warts on her feet. What could be the cause when none of the other members of the family have them? What can I do to treat them so they won't come back?
Under a magnifying glass the roughened surface of a wart often looks like a tiny cauliflower. The little black dots sometimes seen are the ends of blood vessels that the wart has recruited to bring it food. Contrary to well-established belief, the underside of a wart is smooth and round, and the entire wart is confined to the epidermis — the outermost layer of the skin. There are no ‘roots’!
Even without roots, warts can be difficult to destroy.
Warts are infections caused by viruses that are present everywhere, making them among the most common of all childhood skin conditions. The culprit will be one of more than 70 types of human papillomaviruses (HPV). They are contagious, and they are spread when the virus touches a part of the skin where the outer protective layer is broken, either by minor trauma or by moisture. This happens most commonly on the fingers, elbows, knees, and the bottoms of the feet. Warts on the bottom of the feet are called plantar warts – named for the plantar surface (sole) of the foot.
Some people get warts more easily than other people. Warts are more common in children than in adults, partly because of their less mature immune systems and partly because they spend more time in wet-floored locker rooms and in active, close play. Wearing something on the feet in locker rooms and at the pool can prevent many plantar warts.
Most warts will eventually go away on their own, expelled by the body’s immune system. About 25% are gone within 3-6 months and 65% disappear within 2 years. Unfortunately, some warts may persist for years. Warts will not leaves scars, though some of the more aggressive wart therapies might.
Plantar warts often make running, jumping, and even walking, uncomfortable. The tenderness can change posture and cause strain elsewhere in the body. A little wart can be a big problem. Sometimes filing with an emory board and/or wearing a doughnut bandage can alleviate the discomfort. The warts are usually most tender when they are growing most rapidly. Often, the pain will disappear within a few days even if nothing is done. Warts should be treated if they are spreading, unsightly, or continue to be painful.
Treatments abound, varying from as gentle and simple as taping a patch of banana peel on before bed, to as high-tech and powerful as superpulsed carbon-dioxide-laser vaporization.
The active ingredient in most over-the-counter remedies is salicylic acid, a natural substance found in many plants (willow bark) and most fruits. It can be applied either as a liquid or a patch (I prefer the patch). With regular application, many warts will disappear within 12 weeks. These topical treatments often work best if the surface of the wart is disrupted with warm soaks and/or an emory board before application.
If you are not certain that your child has a wart, you may want to have your child’s doctor examine his or her skin before trying an over-the-counter treatment, since some other skin conditions can look similar but need different treatments.
Physicians use many options to treat warts (surgery, lasers, chemical cautery, electrodesiccation, lasers, and even chemotherapy) but freezing is the most common, especially for smaller warts. Gentle freezing repeated every week or two — usually at least 4 times — is the more effective than a single aggressive attempt to freeze. This approach is less painful and much less likely to scar.
Even though these techniques destroy the bulk of the wart viruses, direct destruction is only a part of the story. This can be seen by how poorly they work in people who have immune deficiencies. In the final analysis, it’s our own immune systems that are activated and engage to eliminate the warts. Several newer treatments aim to boost the body’s own immune response, including Imiquimod cream, alpha interferon injections, or oral cimetidine.
Hypnosis has also been tried as a means of activating the immune system. When studied scientifically, hypnotic suggestion has proven to be as powerful as many conventional medical treatments at getting rid of warts. ‘Charming warts’ is particularly effective with children, and is discussed in leading medical textbooks (including the classic Color Textbook of Pediatric Dermatology by Weston, Lane, and Morelli), since many warts regress without therapy. I’ve had success with dabbing warts with paint and letting children watch them glow under a black light! For added impact, I’ve sometimes pressed a painted wart onto a piece of filter paper to make a spot, and then burned the paper. I tell the child it will fall off in two weeks – and it does!
Mark Twain’s quaint solution, then, is consistent with the latest medical science:
“Why, you take your cat and go and get in the graveyard ‘long about midnight when somebody that was wicked has been buried; and when it’s midnight a devil will come, or maybe two or three, but you can’t see ’em, you can only hear something like the wind, or maybe hear ’em talk; and when they’re taking that feller away, you heave your cat after ’em and say, ‘Devil follow corpse, cat follow devil, warts follow cat, I’m done with ye!’ That’ll fetch ANY “wart.”