Liquid nitrogen cryotherapy is one of the most versatile and widely used tools in dermatology. It applies extreme cold — liquid nitrogen boils at -196 degrees Celsius — to destroy targeted tissue through a predictable mechanism: ice crystal formation within cells disrupts cell membranes; the freeze-thaw cycle damages the microvasculature supplying the lesion; the inflammatory response that follows clears the dead tissue. The result is selective destruction of the treated area while surrounding healthy skin recovers.
The technique has been in use for over a century and remains relevant because it works well for a broad range of lesions, is quick to perform, requires no incision, and heals without sutures. In a dermatology practice in Florida, it is used practically every day.
What we treat with cryotherapy
Actinic keratoses are the most common indication. Individual, well-defined lesions respond well to a single freeze. Multiple lesions can often be treated in one session. When AKs are numerous and widespread across a field of sun-damaged skin, photodynamic therapy offers advantages over treating each one individually.
Common and plantar warts typically require multiple sessions spaced three to four weeks apart. The freeze destroys the wart tissue and stimulates an immune response that helps clear the viral infection, but recurrence is possible.
Seborrheic keratoses — the benign, waxy, stuck-on growths that become increasingly common with age — respond well when removal is desired for cosmetic or symptomatic reasons. Solar lentigines (sunspots) and certain other benign lesions can also be treated when appropriate.
The procedure
Liquid nitrogen is applied using either a spray gun or a cotton-tipped applicator, depending on the lesion size and location. Application typically lasts a few seconds. A small halo of freezing in the surrounding normal skin is intentional — it ensures the entire lesion is treated. The area turns white immediately, then pink and swollen over the following hour as it thaws. A blister may form over the next 24 to 48 hours. The blister roof dries into a scab that falls off over one to two weeks as new skin grows in from beneath. No anesthetic is required for most lesions.
Frequently asked questions
Does it hurt?
There’s a sharp stinging or burning sensation during and immediately after the freeze that most patients describe as briefly intense and then quickly fading. For most common warts and AKs, it’s tolerable without anesthesia. Plantar warts are more uncomfortable given the pressure required and the sensitivity of the sole.
Will it leave a mark?
The treated area heals with a flat, typically lighter spot. On most skin tones this fades well over months. On darker skin tones, the hypopigmentation can be more persistent and noticeable — something we discuss when treating patients for whom this matters cosmetically.
How many treatments does it take?
For actinic keratoses, a single treatment often clears individual lesions. For warts, plan for multiple sessions. We reassess response after each treatment and adjust approach if a lesion isn’t responding adequately.