Actinic keratoses (AKs) are rough, scaly tan brown patches on the skin, caused by excessive exposure to the sun, that can sometimes progress into dangerous skin cancers. More than 10 million Americans live with these skin lesions thinking that they represent “age spots”, and far too many people ignore them. Unfortunately, leaving AK’s untreated can have serious consequences. Doctors estimate that 40 percent of skin cancers [squamous cell carcinomas, the second leading cause of skin cancer deaths in the United States] begin as AKs. For this reason, major medical groups —The American Cancer Society, The Skin Cancer Foundation, and the American Academy of Dermatology — all recommend that people with Aks seek review and treatment options for them immediately.
What does Actinic Keratosis look like?
AKs are very common on sun exposed parts of the face, scalp, ears, chest, back and extremities. They present as rough scaly patches of tan to brown skin. Sometimes these patches can become larger and thicker called “hyperkeratotic.” These enlarged lesions may then progress to changed to frank squamous cell carcinomas. Patients may notice increased redness, tenderness, itching, and burning associated with the thickened rough skin. However, these symptoms can be the same for either Aks or squamous cell carcinomas. This is what makes distinguishing between the two so difficult without a simple skin biopsy. Left untreated, squamous cell carcinomas may become larger, go deeper into the skin, and eventually spread to other parts of the body by the lymph nodes. This results in thousands of skin cancer deaths each year, many of which could be prevented with appropriate surveillance and early intervention.
It is impossible to predict if an AK will evolve into a squamous cell carcinoma, or at which point it will happen. Many doctors believe that AKs and squamous cell carcinomas are really the same condition at different stages of a continuing process. This process begins with minor cell damage and, over time, ultimately results in the cell becoming cancerous. These doctors believe that AKs occur in the early stages of the process; squamous cell carcinomas occur in the final stage. One thing, however, is certain: a significant percentage of AKs develop into squamous cell carcinomas. Estimates range from 10 percent to as high as 20 percent over a 10-year period of patients with known actinic keratosis.
Preventing Actinic Keratosis
Long-term exposure to the sun is the single most significant cause of AKs, so the best defense against them is a comprehensive sun protection program. This includes wearing protective clothing and a wide-brimmed hat, avoiding the sun at midday when ultraviolet rays are strongest, staying in the shade as much as possible, and wearing a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 30. Unfortunately many of us already have sun damaged skin and a more aggressive approach is needed.
Treating Actinic Keratosis
Surgical excision, freezing and electrodessication have been the main tools to deal with AK’s. Advanced technology is now available with photodynamic therapy. Levulanic Photodynamic Therapy uses photochemical methods to target minimally to moderately thick Grade 1 or 2 AKs (AKs that have not yet become enlarged and thick). This therapy is unique because it uses light activated drug therapy to destroy AK’s in their early stages. The 2-step process consists of treatment to the affected skin with a weak acid solution which is chemically altered by exposure to certain wavelengths of light.
When levulanic acid is applied to Grade 1 or 2 AKs, the solution is absorbed by the AK cells where it is converted to a chemical that makes the cells extremely sensitive to light. Topical Solution is applied to the AK’s with incubation for the recommended time in order to allow the solution to penetrate the target cells. Target AK’s are porous and absorb more of the levulanic acid than does normal skin cells.
After an incubation period, the painted skin is then treated with blue light with wavelengths in the 400-450 nm, which is the second and the final step in the treatment. The levulanic acid is changed to a toxic substance which kills the abnormal cells in which the acid was concentrated during the incubation period with gentle sparing of the normal skin. Over a few days, these abnormal cells die, crust over and slough off with new skin as replacement. The most common side effects include scaling/ crusting, hypo/hyper-pigmentation, itching, stinging, and/or burning, erythema and swelling.
Photodynamic therapy has proven very effective for thin early actinic kerotosis skin lesions. Treatment has proved to reverse the signs of early skin cancers. Medicare and most insurances pay for this therapy.