Cryotherapy, also known as cryosurgery, is a technique in which a skin lesion is frozen, resulting in death of the cells. It is used in dermatology to treat a variety of skin problems, both benign and malignant. Commonly treated lesions include actinic keratoses and superficial basal cell carcinomas, as well as warts and seborrheic keratoses. Melasma, lentigines, and acne cysts are also commonly treated with cryotherapy. Other lesions including vascular lesions are sometimes also amenable to cryotherapy.
Lesions treated with cryotherapy may become red, crusted, or blister, but usually heal with minimal or no scarring, depending on the intensity of treatment. However, lesions requiring extensive freeze times may result in scarring. Hypopigmentation, especially in darker skin types, is a frequent side effect.
In cryotherapy, liquid nitrogen is applied to the lesion, usually from either a spray canister or by cotton swab. In some cases a metal cryoprobe is applied to the skin and the liquid nitrogen used to cool the probe. Topical or local anesthesia is sometimes applied first, especially when treating children.
Liquid nitrogen is a very cold -196°C. Malignant lesions usually require cooling to -50°C while benign lesions require treatment to -25°C. Freeze times typically range from 5 to 30 seconds with one or two freeze-thaw cycles being applied. Treatment may require repetition at 4-6 week intervals until the lesion is resolved. Overall, cryotherapy is a safe and effective in-office procedure used for numerous dermatological conditions.