Actinic keratoses (AKs) are lesions on the skin caused by exposure to UV rays. These precancerous lesions have the potential to become squamous cell carcinoma. AKs can be caused by unprotected sun exposure or from using a tanning bed and are commonly found in patients over 65. They occur most frequently on the face and the back of the hands but can be found on any area of the skin. AKs can be surgically removed but there are many non-surgical treatment options available. Topical treatment with a medicated cream in addition to surgery or on its own can help eliminate these potentially dangerous lesions.
Detecting Actinic Keratoses
Actinic keratoses are one of the most common diagnoses made by dermatologists. They are small abnormal skin growths that may not even be noticeable by sight at first. AKs may be felt as a rough, raised texture to the skin, although some of the lesions may not be visible on the surface. They can increase in size and become red and inflamed or grow into cutaneous horns that protrude from the skin. It is important to perform regular skin checks for growths that seem unusual or that are growing. Noticing a precancerous lesion early will help minimize the extent of treatment required. For patients that do require treatment for actinic keratoses, however there are several options available.
There are multiple surgical techniques that may be used to remove actinic keratoses. One technique is cryosurgery, which involves applying liquid nitrogen to the lesion to freeze it. The frozen lesion then will blister and fall off. A dermatologist may also cut or scrape the lesion off then apply a chemical to prevent re-growth of the precancerous cells. Laser surgery can be used to eliminate the lesion and may result in less injury to the surrounding tissue and less bleeding.
While surgical removal may be sufficient for some patients, many are also prescribed topical treatments to be used before and after surgery. Topical treatment may be used on its own or in combination with cryosurgery, lasers, peels, and more. Patients with very large areas of AKs may benefit the most from a topical cream since surgery to extensive areas of skin may be both risky and expensive.
5-fluorouracil (5-FU) is a form of topical chemotherapy that can significantly reduce the chances of AKs developing into squamous cell carcinoma. It has successfully been used for over 50 years and has a high cure rate. 5-FU works by reducing DNA synthesis and increasing cell death of AK cells. Most often 5-FU is combined with another ingredient to help increase skin cell turnover.
Often 5-fluorouracil is combined with salicylic acid to increase its effectiveness. Salicylic acid is used in a variety of skin treatments for its ability to remove dead skin cells and help increase skin cell renewal. After the cream is used, there will likely be a stinging sensation and the skin will be red, crusty, and tender. This occurs because the precancerous skin cells are being destroyed.
The combination of fluorouracil and salicylic acid is not commercially available in the U.S. It is available in other countries under multiple brand names including Actikerall® in Europe. Actikerall® includes fluorouracil 0.5% with salicylic acid 10% in the form of a solution. A similar product in the form of a cream can be obtained in the U.S. from a compounding pharmacy. Multiple strengths of fluorouracil can be made ranging from 0.5% to 5%.
Another ingredient that is sometimes combined with fluorouracil is tretinoin. Tretinoin is used as an anti-aging ingredient to increase cell turnover and improve the appearance of the skin. Studies have shown that tretinoin applied topically helps increase the effectiveness of the 5-FU in clearing the actinic keratoses from the skin.
Many conditions affecting the skin can be helped with the use of a chemical peel. The chemical peel can remove superficial lesions by allowing the top layers of the skin to slough off. New, healed skin can then re-grow. Depending on the depth of the chemical peel, there can be some downtime. For a medium-depth peel it can take about 2 weeks for the skin to heal. For treating AKs, chemical peels are effective but may result in a higher recurrence rate than other treatments.
A compounding pharmacy can provide a range of chemical peels from superficial to deep with a variety of ingredients. Chemical peels available from a compounding pharmacy include glycolic, TCA, and Jessner’s.
Diclofenac: This non-steroidal anti-inflammatory drug is sometimes combined with hyaluronic acid for treating AKs. The commercially available formulation Solaraze® includes 3% diclofenac with 2.5% hyaluronic acid.
Imiquimod: This drug was first approved for treating external genital warts. It is now approved in the U.S. for treating AKs as a 5% cream. It may be prescribed to be used daily for two weeks on, two weeks off.
Preventing Actinic Keratoses
Making efforts to prevent the development of actinic keratoses can reduce the need for surgery or prescription medications later on. It is important to practice good sun safety habits at all ages. This includes avoiding sun burns, not using tanning beds, and always using broad spectrum sunscreen. Seeing a dermatologist at least annually for a skin check can help detect precancerous lesions like actinic keratoses before they develop into something more serious.