Warts are small viral skin infections which are frequently treated by wart freezing. They are quite common among children and adolescents but occur in adults as well. They usually appear on the hands, fingers, and feet. For healthy individuals, common warts are harmless and usually go away by themselves in a matter of months or years thanks to your immune system. However, they can be unsightly, embarrassing, and may be painful when on the soles of the feet and near the nails. Treating warts should be easy, safe, and relatively painless, although patience and persistence are usually required.
Wart freezing is one of the most effective ways of treating warts, also known as cryotherapy. It can be done safely at home on common warts with one of several over the counter products, or by your doctor. Each wart freezing treatment is minimally painful, simple and quick, and for a small wart sometimes a single treatment will be enough and the wart will fall off after a few days. Children with many warts may not handle the pain and blistering well. Wart freezing is particularly effective on warts on the back of the hands and fingers, and on mosaic warts on the feet. There is usually little to no scarring.
How does wart freezing work?
Warts feed on small blood vessels. Wart freezing deadens the small blood vessels that the wart feeds off of, and causes a blister to form under and around the wart, detaching it from the surrounding skin, which should effectively kill the wart. The affected skin (hopefully including the wart) should come off within a week.
Wart freezing at home
There are great wart freezing treatments available over the counter, which are safe to use at home. At -70°F / -57°C degrees, these must be applied for 20-40 seconds to be effective. They are available as aerosol sprays applied with a sponge tip. They can be difficult to use on very small warts. Please read the instructions carefully, so as not to damage healthy skin around the wart. We recommend you use Compound W Freeze Off Wart Removal System or Dr. Scholl’s Freeze Away.
I want to try wart freezing at home. What do I do?
First of all, be sure that what you have is truly a wart before you consider wart freezing at home. Please see the pages describing warts, or consult a doctor if unsure.
If you’re sure that what you have is a wart, and want to try wart freezing at home yourself, here are a couple of reputable products you can buy online: Compound W Freeze Off Wart Removal System or Dr. Scholl’s Freeze Away.
After washing your hands and the affected area well with soap and warm water, try to get a sense of how big it is. For a small wart you should be able to freeze the whole thing at once. For a large wart or a plantar wart (which may appear small on the surface but actually goes deep into the skin), you will only be able to freeze part of it at once. Don’t try to overdo it, since if you make too large a blister it will burst and risk further infection. Aim to freeze a small section of it first.
There may be a callous of thick dead skin covering the wart. Soak it in warm water for 15 minutes, and use a pumice stone or emery board to slough off the dead skin. But don’t try to peel off or pick at the skin, because breaking healthy skin will only make it susceptible to more warts, and the viral warts are contagious.
Follow the instructions on the package of your wart freezing product carefully, transferring the cold liquid (Freon) from the can to a new applicator, and pressing the applicator onto the wart. It may be uncomfortable as you will feel the cold, and then slight burning as the skin defrosts. Do not burst any blister that forms, as breaking the skin may lead to re-infection of the affected area, or spreading to other areas. The liquid inside the blister will be reabsorbed without needing to break the skin. The new skin underneath the healed blister will not be contaminated by the virus as long as you don’t damage it. You will likely have to repeat the at-home wart freezing every week until you see the dead tissue (including the wart) come off itself within three weeks. In the meantime, do not pick at the wart.
If you have a wart on the hands or feet that refuses to heal, particularly around the nails, it is a good idea to visit your doctor. It may need to be biopsied (removed and inspected) to exclude the possibility of skin cancer.
Wart freezing by your doctor
The coldest wart freezing is with liquid nitrogen administered by a doctor, which attacks the wart with temperatures as low as -320°F / -195°C, which is much colder than the over the counter wart freezing products. This very cold liquid is applied to the wart with a cotton swab once or twice in a single visit, freezing about one millimetre beyond the edge of the wart. You will feel coldness and then a mild burning sensation as the skin thaws. The skin covering the wart will whiten as if burned, and may darken slightly after some time. Not all family doctors offer this treatment, and if not they may send you to a dermatologist (skin specialist) to have the wart freezing treatment done. Usually you will need to have between one and four visits. For areas with thick skin, more sessions may be required.
To reduce the number of visits required, you should consider using a non-prescription salicylic acid treatment for a couple of weeks before seeing your doctor. A good one to use is Duofilm Liquid Salicylic Acid Wart Remover. Your doctor may suggest following up with it after your wart freezing treatment. “Aggressive cryotherapy”, generally meaning that the liquid nitrogen is applied for 10 seconds, is more effective than “gentle cryotherapy” where the freezing is applied for a shorter amount of time. Keep in mind that with aggressive cryotherapy you are more likely to have pain and blistering, and in young children scarring is possible. Call your doctor to see what costs are involved and check with your insurance to find out about your coverage.