Almost all AKs can be eliminated if treated early, before they become skin cancers. Various treatment options are available, which depend on the growth’s characteristics and the patient’s age and health. Some of these strategies increase sun sensitivity, so check with your doctor, and be especially diligent about using sun protection during the treatment period. Common treatments include the following.
This is the most commonly used treatment method when a limited number of lesions exist. Treatment can be performed in the physician’s office, and no cutting or anesthesia is required. Liquid nitrogen, applied with a spray device or cotton-tipped applicator, freezes the growths. The lesions subsequently shrink and/or blister, become crusted and fall off. Temporary redness and swelling may occur after treatment, and in some patients, pigment may be lost, leaving white spots.
When AKs are numerous and widespread, topical creams, gels and solutions are especially useful by themselves or in combination with another form of treatment. They treat both visible and invisible lesions with a minimal risk of scarring.
One of the most commonly used topical medications for AK is 5-fluorouracil (5-FU) cream or solution, an FDA-approved topical chemotherapy rubbed gently onto the lesion areas once or twice daily for two to four weeks. It can be used on all affected areas. Temporary side effects include redness, swelling, and crusting but for many the therapeutic benefits outweigh any temporary discomfort. 5-FU is available in a variety of formulations, in concentrations ranging from 0.5 percent to 5 percent. The treated areas usually heal within two weeks, there is rarely scarring, and the cosmetic result is good. Imiquimod cream, also FDA-approved, works in a different way: It stimulates the immune system to produce interferon, a chemical that destroys cancerous and precancerous cells. Available in concentrations of 5%, 3.75% and 2.5 %, it is rubbed gently on the lesion, most often two or three times a week for several weeks or months. The cream is generally well-tolerated, but some individuals develop redness and ulcerations.
A gel combining hyaluronic acid, a chemical found naturally in the body, with the non-steroidal anti-inflammatory drug diclofenac may also be effective for people whose skin is oversensitive to other topical treatments.The gel is applied twice a day for two to three months, though courses of treatment under three months have proven less effective. Recent research found that a formula of 3 percent diclofenac twice daily successfully eliminated AKs in organ transplant patients (who are highly susceptible to AKs and skin cancers) and also was effective at preventing invasive squamous cell carcinomas.
In 2012, the FDA approved an effective new topical medicine called Picato® (ingenol mebutate). Available in concentrations of 0.015 and 0.05 percent depending on the AK site, this gel is the first topical therapy to treat AKs effectively with just two or three days application time – three consecutive days for the 0.015% concentration (used on the face and scalp) and two consecutive days for the more concentrated 0.05% gel (used on the trunk and extremities). Skin redness, flaking/scaling, crusting, and swelling are the most common side effects. Picato can cause painful reactions in the first days of treatment, but these usually begin to abate within a week of starting treatment.
Photodynamic Therapy (PDT)
PDT is FDA-approved for the treatment of both AK and Bowen’s Disease, a superficial form of SCC that appears as a persistent red-brown scaly patch. PDT is especially useful for widespread lesions on the face and scalp. A light-sensitizing agent, topical 5–aminolevulinic acid (5-ALA) or methyl aminolevulinate (MAL), is applied to the lesions in the physician’s office. Subsequently, those medicated areas are activated by strong blue or red light, which selectively destroys AKs while causing minimal damage to surrounding normal tissue. Some redness, pain and swelling can result. After the procedure, patients must strictly avoid sunlight for at least 48 hours, as UV exposure will increase activation of the medication, and may cause severe sunburns.
Doctors may combine therapies for a period of time to treat AKs. Typically, treatment regimens combine cryosurgery with PDT or a topical agent like imiquimod, diclofenac, of 5-FU. The topical medications and PDT may also be used serially every three months, six months, or year, as determined by the physician at routine skin examinations. This approach may both improve the cure rate and reduce side effects. One to two weeks of 5-FU followed by cryosurgery can reduce the healing time for 5-FU and decrease the likelihood of white spots following cryosurgery.
Curettage and Electrodessication
When an AK is suspected to be an early cancer, the physician may take tissue for biopsy by shaving off a portion of the AK with a scapel or scraping the lesion with a curette (an instrument with a sharp ring-shaped tip). The curette may also be used to scrape off the base of the lesion. Bleeding is stopped with an electrocautery needle or by applying trichloroacetic acid (TCA). Local anesthesia is necessary.
This method, best known for reversing the signs of photoaging, is also used to remove some superficial actinic keratoses on the face, especially when other techniques have not succeeded. Trichloroacetic acid (TCA) and/or similar chemicals are applied directly to the skin, causing the top skin layers to slough off. New skin generally regrows within a few weeks. This technique may require local anesthesia and can cause temporary discoloration and irritation.
The skin’s outer layer and variable amounts of deeper skin are removed using a carbon dioxide or erbium YAG laser. Lasers are effective for removing actinic cheilitis from the lips and AKs from the face and scalp. They give the physician good control over the depth of tissue removed. Lasers are also used as a secondary therapy when topical medications or other techniques are unsuccessful. However, local anesthesia may be required. The risks of scarring and pigment loss are slightly greater than with other techniques.