Actinic keratosis: What It Is | Almirall

Dermatology

Actinic keratosis

Actinic keratosis, or solar keratosis, is an area of sun-damaged skin occurring mostly in areas that are chronically exposed to ultraviolet (UV) radiation.

It is usually found on the face, bald scalp, forearms, back of the hands and lower legs.

Actinic keratoses can grow to a centimeter or two in diameter. Although at first they may be difficult to see, they are easily distinguished because they are usually rough, scaly patches. Their appearance is variable.

In fact, the same person can have different actinic keratoses of different colors, thicknesses, and sizes.

Are there different types of actinic keratosis?

Clinicians distinguish between several types of actinic keratosis based on how the lesions appear and feel on the skin. The most common variety is hyperkeratotic, which presents as thick, scaly, or wart-like growths, while the pigmented type appears as brown, freckle-like patches. Other forms include atrophic lesions, which look like thin, red sores, and actinic cheilitis, which specifically affects the lips, causing persistent dryness and cracking. Regardless of the specific appearance, all types require monitoring as they represent different visual manifestations of the same precancerous cell damage.

Risk factors: actinic keratosis and sun exposure

Exposure to accumulated UV radiation over the years is mostly responsible for the development of actinic keratosis hence, this is why it occurs most commonly in older people. This accumulation results from sunbathing, from using tanning beds or from working or playing sports outdoors.

It is true that, while sunbathing affords certain beneficial effects—for instance, sunlight is necessary for the skin to produce vitamin D—excessive exposure to UV light causes mutations in the DNA of skin cells. This favors premature photoaging and the development of actinic keratosis and skin cancer.

How is it diagnosed?

Usually, a dermatologist will only need to examine the lesions to be able to diagnose actinic keratosis. Only when in doubt, the doctor will do a biopsy, which involves removing and sending off a sample of the lesion for microscopic examination in the laboratory.

What are the symptoms of actinic keratosis?

Actinic keratosis usually occurs in adults with fair skin in the form of rough, scaly spots, plaques or lumps. These spots can vary in color, can present as single or multiple lesions, and appear on sun-exposed areas. The surrounding skin may also be affected and look a different color or present small broken blood vessels. Even if it looks normal, this surrounding skin which is called field of cancerization can present alterations that can only be seen under a microscope.

Although actinic keratoses does not usually give any symptoms, they can sometimes cause itching or bleeding. You should always check with your doctor if you notice any of these symptoms.

How is actinic keratosis treated?

It is very important to identify and treat actinic keratosis lesions to reduce the disease progression to a skin cancer. The number of lesions is one of the factors that your doctor will take into account in the choice of treatment, although other factors such as your age, treatment adverse effects and your preferences will also be taken into account.

Actinic keratosis can be treated by eliminating the lesions, either with techniques such as surgery, cryotherapy or laser, or with topical medications (applied to the skin).

FAQs

Can actinic keratosis be cured?

Actinic keratosis lesions can heal and disappear spontaneously or through treatment. However, it is very common for old lesions to recur or for new ones to appear. The presence of just one actinic keratosis lesion is already a sign that chronic damage from solar radiation has occurred, and hence there is a risk that other lesions could appear. Therefore, if you have actinic keratosis, your doctor will monitor you regularly, and will recommend that you seek consultation if you notice new lesions or any changes in the ones you already have.

How can we prevent actinic keratosis?

Protecting yourself from the sun is essential to prevent the appearance of actinic keratosis and slow progression. Strict adherence to the following measures is key to keeping actinic keratoses under control:

Is actinic keratosis a type of skin cancer?

Actinic keratosis is an uncontrolled proliferation of keratinocytes, the most abundant cells of the epidermis (the outermost layer of the skin), that become abnormal. Some actinic keratoses can turn into a type of skin cancer called epidermoid carcinoma or invasive squamous cell carcinoma. Although rare, this type of cancer can spread to other tissues, and it is therefore recommended to treat all actinic keratoses.

Furthermore, a person with actinic keratosis is at higher risk of developing any type of skin cancer compared to another person of the same age who does not. People who have a higher number of actinic keratoses also run a higher risk of skin cancer.

Is actinic keratosis hereditary?

Actinic keratosis is not hereditary, although some of the factors that favour its appearance, such as fair skin or freckles, are so. Actinic keratosis is not contagious.

What is the clinical course of actinic keratoses?

Some actinic keratoses resolve spontaneously, especially if sunscreen or protection is used, although most remain as they are. Others may progress into invasive squamous cell carcinoma. Unfortunately, it is impossible to know in advance which ones will, in fact, develop into invasive squamous cell carcinoma. The clinical course of the condition cannot be predicted.

References