Warts are noncancerous tumors that develop due to human papillomavirus (HPV) infections. Cryosurgery, or cryotherapy, is a common way to remove them. It involves freezing off the targeted cells and tissues.
There are several different types of wart, and various strains of HPV can cause them. This virus passes on through skin-to-skin contact.
Most warts are painless and harmless, and many go away on their own after a few
But depending on the location, size, and type of a wart, a person may wish to have it removed. In this case, cryosurgery is an option. A dermatologist can perform it, or, for a smaller wart, a person might try an over-the-counter freezing kit.
In this article, we explore cryotherapy, including the procedure, the reasons that people have it, and how effective it is.
A dermatologist usually begins by scraping dead skin cells from the wart with a scalpel. This exposes more of the surface skin containing the virus to the freezing agent, which is liquid nitrogen.
In some cases, the doctor may instruct the person to perform this scraping at home the night before the appointment.
Next, the dermatologist uses a probe, cotton ball, dipstick, or a tool called a cryostat gun to deliver a dose of liquid nitrogen to the wart. Preferences and methods of application vary, but all in all, the liquid nitrogen is typically in contact with the skin for 10–20 seconds.
Current guidelines recommend having two cryosurgery sessions for wart removal, but more may be necessary, depending on the size of the wart.
Liquid nitrogen-based removal is safe for most healthy people. A dermatologist may recommend a different approach, however, depending on the person’s age and the overall state of their health.
It is not always necessary to remove warts through cryosurgery. They often resolve without treatment, especially in children.
As people move into adulthood, they may find that warts require medical intervention, especially if they:
- cause discomfort or pain
- cause friction or pressure
- have persisted for more than a few years
- cause or contribute to low self-esteem, anxiety, or depression
- keep a person from walking comfortably or gripping objects, or cause any other impairment
- are plantar warts, which form on the soles
It other cases, health issues make it important to see a professional. The American Academy of Dermatology recommend that people with any of the following see a dermatologist for wart removal:
- a compromised immune system
- multiple warts across the body
- warts that bleed, itch, or hurt
- warts on the face or genitals
Though many doctors remove warts with cryosurgery, there is limited research to support using this procedure rather than concentrated salicylic acid treatment.
However, cryotherapy may be the most effective approach to certain kinds of warts. For example, a 2012 review found that the procedure had a 60–86% success rate as a treatment for common and genital warts.
A retrospective study from 2015 placed the success rate for common wart removal at
A 2019 study found a slightly higher success rate for the cryosurgical removal of genital warts:
Plantar warts tend to be both the hardest to treat, as they
It is important to note that cryosurgery, or cryotherapy, does not cure the underlying HPV infection. Currently, no treatment can do so.
Warts may heal and regrow. In other cases, the body may rid itself of the virus by destroying any remaining HPV cells after wart removal.
No over-the-counter wart removal product contains liquid nitrogen. Instead, they contain a mixture of dimethyl ether, propane, and sometimes isobutane.
Home freezing products may not be as effective as cryosurgery. Though they contain the same acids that doctors use, the acids are at much lower concentrations, and their freezing chemicals are also less powerful.
Home care products may be able to remove small warts, but they may only temporarily reduce the size or appearance of larger growths.
People sometimes use other methods, such as applying duct tape to the area for several weeks. However, these approaches have no or very slim scientific backing.
Most people experience minor pain during cryosurgery and a burning sensation when the skin thaws afterward.
During and immediately after the procedure, the treatment site may change color and swell. There may also be soreness for a few days.
About 24 hours after the procedure, a blister forms around the wart, and it resolves within 2 or 3 days.
The entire recovery typically takes around a week, and it is important to keep the area clean, dry, and free from friction or pressure throughout this time.
Any additional risks and complications depend on the type, size, and location of the wart.
Usually, plantar warts, large warts, and those in areas with a lot of pressure or friction tend to cause the most pain and complications, such as scarring or tissue damage.
Other potential complications of cryosurgery include:
- a prolonged healing process and the development of ulcers
- temporary nerve damage near the site
- a permanent loss in skin coloration
- skin lesions that keep returning
- hair loss, according to one review
Dermatologists can reduce the risk of complications by limiting contact with liquid nitrogen to under 30 seconds.
A secondary infection developing in the site of cryosurgery is uncommon. The symptoms include:
- pus or white, yellow, or brown fluid from the blister
- a fever
- increased, throbbing pain
- no signs of the area healing after a few days of care
Anyone with symptoms of a secondary infection should contact a doctor, who may prescribe a topical antiseptic or an oral antibiotic.
arts disappear without treatment. It may also be possible to remove small warts with over-the-counter products.
If warts are large, numerous, or persistent, it may be best to have them professionally removed. This is particularly beneficial for people with certain chronic conditions or weakened immune systems.
To remove a wart, a dermatologist might use cryosurgery, or cryotherapy. This involves briefly applying liquid nitrogen to the skin. The healing period is about 1 week, and complications are rare, though they can occur.
Cryosurgery does not treat the underlying HPV infection that causes warts, and warts may regrow, in the same spot or elsewhere.
Some at-home wart freezing products are available for purchase online: