They’re usually harmless, painless and go away on their own. But few skin conditions are as annoying and unsightly as warts ‘ contagious, non-cancerous skin growths, caused by the human papillomavirus (HPV), that can arise at any age.
"More than 95 percent of Canadians have been exposed to HPV by the time they become adults, even if they demonstrate no clinical signs of having warts," says Dr. Sunil Kalia, a professor in the department of dermatology at the University of British Columbia and a dermatologist at the Vancouver General Hospital. "It’s usually contracted in public environments, such as swimming pools and showers, but it also spreads through skin-to-skin contact."
When the virus infects healthy skin cells, instead of destroying them, it triggers them to grow, resulting in warts. There is no research indicating who is most susceptible, but usually the virus requires a break in the skin (a cut or even the tiny cracks associated with dryness or atopic dermatitis) for it to enter, says Kalia.
Unlike skin tags (benign skin growths) and moles, warts have a rough, uneven texture. The main types include common warts, which grow on hands and fingers and are grey-brown in colour; plantar warts, which develop on the feet and look brown and scaly; flat warts, which usually appear on the face and have smooth, flat, flesh-toned tops; and genital warts, which feature distinctive, finger-like growths in the genital region. Although it is possible to spread a wart from one part of your body to another, it’s unlikely, as there are more than 100 varieties of HPV and each prefers a different area.
No matter which type of wart you suspect you have, see your GP or dermatologist to get a diagnosis and rule out the possibility of skin cancer (most of us can’t tell the difference, says Kalia). Because genital warts spread through sexual contact and are linked to cervical cancer, they must be treated by a doctor. Flat warts, too, require intervention ‘ their small size and flat shape mean that over-the-counter (OTC) preparations can often damage the surrounding skin. Always seek medical advice if you have any type of wart that is sore or bleeding, has changed in appearance or has not responded to treatment.
Warts often disappear on their own within 12 to 18 months. "Most warts except for flat warts ‘ because they are more stubborn ‘ can spontaneously resolve," Kalia explains. "But usually if they don’t go away within one year to 18 months, it is less likely they will ever resolve without treatment." Because they are contagious and there’s a small risk that they can develop into skin cancers, it’s best to clear them up more quickly, either by using OTC remedies or going to your doctor’s office for treatments.
If you get confirmation from a doctor that you have a common or plantar wart, you can start with these remedies.
Topical salicylic acid treatments
Examples: Dr. Scholl’s Clear Away Liquid Wart Remover Fast-Acting Liquid;
Compound W Wart Remover Fast-Acting Liquid; Duoplant Wart Remover Kit (plantar warts only); Soluver Plus
How they work: "Salicylic acid doesn’t kill HPV, but it changes the environment so the wart can’t survive," says Pindy Janda, a patient-care pharmacist with London Drugs in Vancouver. "It dissolves the substance that causes skin cells to stick together, which in turn dissolves the wart." Available OTC in up to a 40 percent concentration, salicylic acid treatments come in the form of liquids, gels, bandages and adhesive discs. The latter two types are most effective, says Janda, since they help ensure the wart is receiving a constant supply of medicine.
Need to know: Most salicylic acid remedies should be applied every 24 to 48 hours. In between applications, soak the wart in water and, after letting the area dry, use a pumice stone to gently remove any skin that easily sloughs off. According to Janda, it takes six to 12 weeks for a wart to gradually peel away in layers. Though salicylic acid medications are considered safe, people with decreased circulation, including pregnant women, seniors and diabetics, should consult a doctor before using them.
Topical cryotherapy treatments
Examples: Compound W Freeze Off Wart Removal System; Dr. Scholl’s Dual Action Freeze Away Wart Remover; Wart Freeze
How they work: While in-office cryotherapy uses liquid nitrogen to freeze away warts, the OTC version features dimethyl ether and propane for a low-level freezing effect. Treatment involves holding a medicated applicator to the wart for about 40 seconds. Like salicylic acid, it destroys the skin cells that are infected with HPV (but not the HPV virus itself).
Need to know: Although some cryotherapy products claim to destroy warts in one treatment, most people need repeat applications, says Janda. Because there are no clear guidelines on how frequently this medication can be used, consult with your doctor, advises Kalia. Treatment time is about six to 12 weeks, during which you should soak and gently buff away the dead skin as the wart peels off. Janda says, "There is a risk of nerve damage and scarring if these are used for an excessive amount of time on a very stubborn wart." Again, if you have impaired circulation, talk to your doctor first.
DIY and topical naturopathic treatments
Examples: Duct tape; raw garlic; oral zinc tablets
How they work:
Duct tape: A study from the Cincinnati Children’s Hospital Medical Center compared cryotherapy with duct tape treatments and found the latter was significantly more effective at clearing warts. The tape was cut to the size of the wart and applied for six days; it was then removed and the wart was soaked, buffed and left exposed for 12 hours. The cycle was repeated for up to two months. "The tape may cause a local inflammatory reaction that stimulates the immune system to clear the wart," says Theresa Jahn, a naturopathic doctor in Toronto.
Raw garlic: Other research indicates raw garlic is effective when a thin slice is applied to the wart daily and covered with a bandage; it may work similarly to duct tape in stimulating an immune reaction.
Oral zinc tablets: Reduced zinc levels may be associated with persistent, recurring warts. Several studies have shown resolution of warts with oral zinc sulfate supplementation over one to two months.
Need to know: Duct tape and garlic treatments are considered safe, but may trigger minor skin irritation. Garlic also leaves a strong odour and may itch, cause redness or temporarily darken the surrounding skin. Jahn recommends using duct tape to hold the garlic in place, changing the garlic and rinsing and buffing the wart daily. In studies, improvements were seen in three to nine weeks. Zinc sulfate may cause gastrointestinal upset, nausea and itching; avoid prolonged use at high doses. (It is usually not used on its own, but as part of a comprehensive treatment plan.)
Doctor’s office treatments
If the wart doesn’t respond to over-the-counter remedies after four to six weeks, or if you have flat or genital warts, you’ll need to see your doctor for treatment. For most warts, Kalia prefers a combined approach using prescription salicylic acid preparations (available at up to 60 percent concentration) and cryotherapy (usually 10 to 12 treatments, each two weeks apart). The in-office version uses liquid nitrogen at a much lower temperature than OTC methods; it is therefore more effective, requiring fewer treatments. For very stubborn warts, other treatments include bleomycin injections (which kill the virus), retinoids (which disrupt skin-cell growth) and immune-enhancing medications (which help your body fight the virus).
Typically pink or flesh-coloured in appearance, genital warts affect the moist tissues of the genital area. Although they sometimes grow in clusters, they are often tiny and difficult to see; your healthcare provider can make a diagnosis. Cryotherapy and the immune-enhancing medication imiquimod are the most effective treatments, but you need a prescription, says Kalia. He also recommends that women between age 16 and 26 receive the Gardasil vaccine, which protects against four different subtypes of HPV (two of which account for 75 percent of cervical cancer cases). "Even if you already have genital warts, you’re still at risk because you may not be protected from the other subtypes," he says.