How to Freeze Actinic Keratosis Lesions

Actinic keratosis lesions are scaly spots that form on the skin as a result of sun damage. They vary in size and color, usually appearing on areas of skin that have been exposed to sunlight, such as the face, hands, arms and ears. Often called "sun spots," they can be the same color as the skin, tan, red, pink, brown or a combination of colors. The lesions can be flat, or raised above the skin's surface, and range from very small to more than an inch in diameter. Actinic keratosis is considered precancerous because some of the lesions can develop into skin cancer. Freezing, or cryotherapy, is a common method of removing actinic keratosis.

Things You'll Need

• Hospital grade antiseptic cleanser and sterile gauze pads or individually packaged antiseptic cleansing cloths
• Lidocaine 1% premeasured in a syringe or topical anesthetic, optional
• Sterile scalpel or surgical scissors
• Liquid nitrogen in spray form, or a cryoprobe or sterile, cotton-tipped applicator and liquid nitrogen poured in a styrofoam cup

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Instructions

• 1

  Clean the affected area with the antiseptic cleanser using either the sterile gauze pads or individually packaged cloths. Apply topical anesthetic or inject 1% lidocaine, if desired.

• 2

  Remove (debride) dead tissue from the actinic keratosis lesion by scraping it with a scalpel or surgical scissors. This allows the liquid nitrogen to access the lesion more effectively.

• 3

  Hold the spray nozzle about 1 cm away from the lesion and spray using a pulsing action. A cone or disposable otoscope speculum can be used to keep the liquid nitrogen concentrated on the lesion and away from healthy skin. The boiling point of liquid nitrogen is -196 degrees and the skin's heat will transfer to the liquid nitrogen, causing it to "boil" and evaporate. If a cryoprobe is used, the skin's heat will transfer through a copper probe placed on the lesion. When using the cotton-tipped applicator, dip it in the liquid nitrogen in the styrofoam cup and touch the tip to the lesion. Do not reuse the liquid nitrogen on another individual.

• 4

  Allow the lesion to freeze and form an ice ball. The longer the freezing time, the better the "cure rate." Lesions frozen for five seconds have a cure rate of 39 percent compared to 83 percent for lesions with a freezing time of 20 seconds.

• 5

  Thaw the lesion slowly, then refreeze it. This process causes the most cell damage to the lesion. Inflammation will develop at the site, possibly causing swelling and redness, and a blister may form. This is the body's natural response to cell death (injury). Cryotherapy may need to be repeated multiple times.