Cryosurgery for Common Skin Conditions - American Family Physician

Mechanism of Action Liquid nitrogen, which boils at −196°C (−320.8°F), is the most effective cryogen for clinical use. It is particularly useful in the treatment of malignant lesions. Temperatures of −25°C to −50°C (−13°F to −58°F) can be achieved within 30 seconds if a sufficient amount of liquid nitrogen is applied by spray or probe. Generally, destruction of benign lesions requires temperatures of −20°C to −30°C (−4°F to −22°F). Effective removal of malignant tissue often requires temperatures of −40°C (−40°F) to −50°C. Irreversible damage in treated tissue occurs because of intracellular ice formation. The degree of damage depends on the rate of cooling and the minimum temperature achieved. Inflammation develops during the 24 hours after treatment, further contributing to destruction of the lesion through immunologically mediated mechanisms. C ryosurgery has been used to treat skin lesions for approximately 100 years. The first cryogens were liquid air and compressed carbon dioxide snow. Liquid nitrogen became available in the 1940s and currently is the most widely used cryogen. Over the past 50 years, much experience has been gained in the use of cryosurgery to treat skin lesions. The cotton-tipped dipstick method of liquid nitrogen application has been popular in the management of common benign lesions (Figure 1, Cryosurgery is a highly effective treatment for a broad range of benign skin problems. With appropriate instruction and supervised experience, family physicians can master the technique quickly. Cryosurgery is best suited for use in patients with light skin and for treatment of lesions in most non–hairbearing areas of the body. Spray methods include the timed spot freeze technique, the rotary or spiral pattern, and the paintbrush method. Benign skin lesions that are suitable for freezing include actinic keratosis, solar lentigo, seborrheic keratosis, viral wart, molluscum contagiosum, and dermatofibroma. Cryosurgery requires little time and fits easily into the physician’s office schedule. Advantages of this treatment include a short preparation time, low risk of infection, and minimal wound care. In addition, cryosurgery requires no expensive supplies or injectable anesthesia, and the patient does not have to return for suture removal. Potential side effects include bleeding, blister formation, headache, hair loss, and hypopigmentation, but rarely scarring. Skin lesions often can be treated in a single session, although some require several treatments. (Am Fam Physician 2004;69:2365-72. Copyright© 2004 American Academy of Family Physicians) Cryosurgery for Common Skin Conditions