Actinic Keratosis

What is it?
Actinic keratosis is a skin growth that is scaly and irregular in shape. This type of growth is an early sign of skin cancer, often leading to squamous cell carcinoma. Referred to as actinic keratoses (AKs) when there is more than one. Also known as sun spots, senile keratoses, solar keratoses, and senile warts.
Who gets it?
People who expose their skin to the sun frequently, especially without wearing sunscreen, are more likely to develop actinic keratoses. They are also more common in people with red hair and freckles. Although AKs used to be more common in the elderly, they are now seen more often in younger people due to changes in our environment and lifestyles.
What causes it?
Actinic keratoses are caused by repeated and prolonged exposure to the sun’s ultraviolet rays. Ultraviolet B (UVB) radiation causes the cells on the surface of the skin to undergo mutations that can cause abnormalities in certain genes. One particular gene that is affected is TP53, a gene that suppresses tumors. When this gene is damaged, it allows cancer-prone cells to divide, which creates the growths known as actinic keratoses. They can eventually develop into skin cancer.
What are the symptoms?
Actinic keratoses appear as small, scaly growths on areas of the skin that have received sun exposure. They are most common on the face, including the scalp and ears, as well as on the backs of the hands. They may first look like a flat, red spot, but become thicker and scaly as they grow larger. They can also be black or brown.
How is it diagnosed?
A specialist in skin conditions, called a dermatologist, can recognize actinic keratoses during a routine skin exam. AKs that are larger and very thick need to be removed through a procedure called a biopsy. The doctor will numb the area, then cut the growth from the skin. The growth is then examined under a microscope for abnormalities. Any skin growth that undergoes a change in appearance, such as bleeding or rapid growth, should be examined. It is important to diagnose actinic keratoses in the early stages, before they can become cancerous.
What is the treatment?
The treatment for actinic keratoses depends upon the number and size of the lesions. If the growths are small and show no signs of malignancy (cancer), they can be frozen with liquid nitrogen, called cryotherapy. Your doctor will want to recheck the growth areas at a later time to ensure the skin is clear. Patients with many AKs may be treated with photodynamic therapy. With this method, the doctor applies a chemical called aminolevulinic acid (ALA) to the skin. After it is absorbed, the doctor shines a special blue light onto the skin, which acts on the ALA solution in a way that destroys any cancerous cells. Over a short period of time, the AKs become crusty, and then heal. AKs may also be treated with a chemotherapy cream called 5-fluorouracil. When the lesions become red and crusty, application of the cream is stopped so the lesions can heal. Other promising treatments focus on stopping the gene mutations that cause AKs or altering the skin’s immune system so it rejects the pre-cancerous cells.
Self-care tips
You can prevent actinic keratosis by avoiding sun exposure during the peak hours of 10 a.m. to 2 p.m. If you do spend time in the sun, wear sunscreen with a SPF of at least 15, a hat, and light, protective clothing.