Cryotherapy for skin is a procedure that uses extreme cold, almost always liquid nitrogen, to freeze and destroy unwanted skin growths. It’s one of the most common in-office dermatology procedures, used to treat everything from warts and sun spots to precancerous patches and certain skin cancers. The treatment is fast, typically taking only seconds per spot, and rarely requires any anesthesia.
How Freezing Destroys Skin Cells
Liquid nitrogen reaches temperatures around minus 196°C. When applied to the skin, it damages tissue in two ways. First, it destroys the tiny blood vessels feeding the targeted area, cutting off its blood supply. Second, it forms ice crystals inside and between cells. As tissue freezes, ice crystals pull water out of cells. As it thaws, water rushes back in, causing cells to swell and burst.
The target temperature for destroying benign growths is minus 20°C. Cancerous cells are more resistant and require about minus 50°C. One important detail: melanocytes, the cells that give skin its color, are extremely sensitive to cold and can be damaged at just minus 5°C. This is why pigment changes are one of the most common side effects.
Conditions It Treats
Cryotherapy can treat over 50 types of skin lesions. The most common everyday uses include:
- Warts: common warts, plantar warts, and genital warts
- Sun damage: age spots (solar lentigines) and actinic keratoses, the rough scaly patches that can become cancerous
- Molluscum contagiosum: the small, dome-shaped bumps caused by a viral infection
- Skin tags and benign growths: including seborrheic keratoses and certain cysts
- Keloid and hypertrophic scars: raised, thickened scars from previous injuries
For precancerous lesions, actinic keratoses are by far the most frequent target. Cryotherapy also treats Bowen’s disease, a very early form of squamous cell carcinoma that hasn’t spread beyond the skin’s surface. In some cases, dermatologists use it on basal cell carcinoma and squamous cell carcinoma, though surgery is more common for confirmed skin cancers.
What the Procedure Feels Like
Your dermatologist will spray liquid nitrogen directly onto the lesion using a handheld device, or occasionally apply it with a cotton swab or metal probe. Each spray lasts roughly 5 to 30 seconds depending on the type and size of the growth. For a common wart, a typical treatment involves about 10 seconds of freezing after an ice ball forms on the skin’s surface, with a 2-millimeter margin around the lesion.
You’ll feel a stinging or burning sensation during the freeze. Some people describe it as an intense cold that briefly becomes painful. The discomfort usually fades within a few minutes. Most benign growths need only a single freeze-thaw cycle per session. Malignant lesions may require two or more cycles, with a few minutes of complete thawing between each round, because repeated freezing causes significantly more tissue destruction.
Some conditions clear in one visit. Others, like stubborn warts, may need multiple sessions spaced about four weeks apart. Three sessions is a common treatment plan for warts.
How Effective Is It
Success rates vary considerably by condition and technique. For actinic keratoses, the freeze time matters a lot. A single 5-second freeze clears about 39% of lesions at three months, while freezing for more than 20 seconds pushes the clearance rate to 83%. Using two freeze-thaw cycles instead of one also improves results without adding significant side effects.
For plantar warts, cryotherapy has a cure rate around 46%, which is better than salicylic acid alone (about 14%) but lower than some newer combination treatments or laser therapy. Common warts on hands and fingers tend to respond better than plantar warts, since the thick skin on the soles of the feet insulates the virus.
Healing and Recovery
The treated area turns red and may sting or swell for the first hour or two. Within 24 to 48 hours, the spot darkens to a brown, reddish-brown, or sometimes bluish color. A blister often forms, and occasionally it fills with blood rather than clear fluid. This is normal. Don’t break the blister open, as the intact skin acts as a natural bandage while new tissue forms underneath.
If the blister breaks on its own or the area weeps, the site may develop a crust. You can apply petroleum jelly to keep it moist until the crust falls off naturally. Most treated areas heal within 7 to 10 days for small spots, though some sites take up to three weeks, particularly on the lower legs and feet where circulation is slower.
Side Effects and Pigment Changes
The most common lasting side effect is a change in skin color at the treatment site. Hypopigmentation, where the skin becomes lighter, happens because melanocytes are so sensitive to cold. This lightened patch can persist for months or even permanently, often with a slightly darker ring around the edge. Hyperpigmentation, or temporary darkening, is also possible and tends to fade over time.
These pigment changes make cryotherapy a bigger consideration for people with darker skin tones. Clinical guidelines list dark skin as a relative contraindication because of the risk of noticeable, long-lasting lighter spots that may be cosmetically unacceptable. If you have darker skin, it’s worth discussing this with your dermatologist before treatment, as alternative approaches may produce better cosmetic outcomes.
Other possible side effects include mild scarring, temporary numbness if a nerve is near the treatment site, and in hair-bearing areas, permanent hair loss at the treated spot.
Who Should Avoid Cryotherapy
Certain conditions make cryotherapy unsafe. People with cold urticaria, a condition where cold exposure triggers hives, should not have the procedure. The same applies to Raynaud’s disease, cryoglobulinemia (where abnormal proteins in the blood thicken in cold temperatures), and any area with poor circulation.
Cryotherapy is also not appropriate when a tissue sample is needed for diagnosis, since the freezing process destroys the cells. Aggressive or recurring skin cancers in high-risk locations like the temples, nasolabial folds, or eyelid margins are typically better treated with surgical techniques that allow the margins to be checked under a microscope. People prone to keloid scarring should approach cryotherapy cautiously, as the treatment itself can sometimes trigger the kind of scarring it’s used to treat in other contexts.