Liquid nitrogen removes warts by freezing them, which causes them to die, reports About.com. A blister forms at the treatment site and eventually forms a scab that falls off, although the surrounding tissue is left unharmed, explains WebMD.
Liquid nitrogen is applied to a wart using a probe, such as a cotton swab or in spray form, according to About.com. Treating a wart with liquid nitrogen generally doesn't cause a scar to develop, as the surrounding connective tissue remains intact. However, a blister typically forms at the treatment site within hours and later dries. If the blister breaks open, a person can avoid spreading of the wart virus by not touching the fluid and cleansing the area, states WebMD. The treated area generally heals within seven to 14 days, although pain can persist up to three days.
Removing a wart with liquid nitrogen can be painful, and in some cases, a topical anesthetic is used to numb the treatment area prior to applying it, explains WebMD. Additionally, a knife may be used to aid in the removal of some of the wart’s tissue before the liquid nitrogen is applied. A few treatments spread at intervals of one to three weeks may be required for the complete removal of a wart using liquid nitrogen treatment. This procedure is usually carried out in a doctor’s office and is completed in minutes.