This simple procedure usually takes less than a minute and can be done in your doctor's office. Your doctor applies the liquid nitrogen using a probe or a cotton swab, or he or she sprays the liquid nitrogen directly onto the skin growth.
Cryotherapy can cause moderate pain that can last up to 3 days. Healing is generally quick (7 to 14 days). Expect a blister to develop within hours after treatment. The blister will dry up over the next few days, and the keratosis should fall off.
Cryotherapy causes little or no scarring, though some people, particularly those with darker skin, experience permanent skin-color lightening. Talk to your doctor to see if cryotherapy is right for you.