How does cryotherapy work?

Cryotherapy works by taking advantage of the destructive force that freezing temperatures have on skin cells. At such low temperatures, ice crystals form inside the cells, which destroy them when the ice thaws.

The procedure:

Cryotherapy is usually performed by using liquid nitrogen as a cooling agent. The super chilled liquid is sprayed onto the tissue to be destroyed, or may be applied by using a chilled forcep, or simply by dabbing it on with a cotton bud.

After the session:

Patients undergoing cryosurgery usually experience mild-to-moderate localized pain, redness and swelling. Occasionally, blisters that contain clear to blood-filled liquid may develop. A blister may be left untouched unless it is causing excessive local discomfort or trouble. It will usually dry up, form a scab and peel off within a couple of weeks. Alternatively it can be punctured, in which case an absorbent dressing may be needed for the following few days in order to absorb the discharge.

Cautions:

The freezing of lesions on the forehead or temples may result in headaches. Very rarely, treatment on hair-bearing areas may also result in permanent hair loss.

A change in pigmentation (hypo- or hyper-pigmentation) occasionally occur especially with longer freeze times. It is less noticeable in patients with a light complexion and usually improves over time.

Minor scarring may also occur, especially when longer freezing times are required such as for malignant or resistant conditions like plantar warts.

Although rare and usually temporary, sensory nerve damage has been reported. It may take up to one or two years for sensation to return to the area.