Actinic Keratosis

Actinic keratosis is a rough, scaly patch on sun-exposed skin that develops from years of ultraviolet exposure. While most patches are harmless, they represent precancerous changes that can potentially develop into skin cancer, making early detection and treatment important for your skin health.

solar keratosis

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Table of contents

• What is actinic keratosis?
• What causes actinic keratosis?
• Who is at risk?
• What does it look and feel like?
• Possible complications
• How is it diagnosed?
• Treatment options
• How to prevent actinic keratosis

What is actinic keratosis?

Actinic keratosis is a precancerous skin condition that appears as rough, scaly spots on areas of your skin that have been exposed to the sun over many years^[1]. The term “precancerous” means that these patches have the potential to develop into skin cancer, although this happens in only a small percentage of cases^[3].

These patches commonly appear on the scalp (especially in areas with thinning or no hair), face (including lips, nose, and ears), arms, and the back of your hands^[1]. However, they can form on any sun-exposed area of your body^[2].

Actinic keratosis is the most common type of skin precancer—a condition where cells have begun to change abnormally but have not yet become cancerous^[1]. Each year, more than 40 million Americans develop actinic keratosis^[1]. In some regions, up to 25% of people aged 60 years and over have at least one of these patches^[3].

What causes actinic keratosis?

Too much exposure to ultraviolet (UV) light—a type of invisible radiation from the sun or tanning beds—is the main cause of actinic keratosis^[1]. UV rays damage the DNA in your skin cells, specifically targeting the outer layer of cells called keratinocytes^[1].

This damage builds up over time through years of sun exposure^[2]. Even short periods of sun exposure on a regular basis can accumulate over your lifetime and increase your risk^[4]. The damage causes these cells to grow abnormally, leading to the rough or scaly spots on your skin^[1].

Who is at risk?

Anyone with a history of sun exposure can develop actinic keratosis, but certain factors make some people more likely to get these patches^[1]:

• Being male
• Having a compromised immune system, such as people taking immunosuppressive drugs after organ transplants
• Having a light skin tone, particularly people with red or blonde hair and blue or light-colored eyes
• Having a history of actinic keratosis or skin cancers
• Having had many years of sun exposure or tanning bed use
• Living closer to the equator where sun exposure is more intense

Fair-skinned individuals are particularly vulnerable because they have less melanin pigment in their skin, which makes them more susceptible to sunburns and the damaging effects of UV radiation^[4]. Actinic keratosis increasingly affects older people due to cumulative lifetime exposure to the sun^[4].

What does it look and feel like?

Actinic keratosis can vary widely in appearance, and you may notice changes in how your skin looks or feels^[2]. Many types feel like sandpaper when you touch them^[1]. In fact, these patches are often more easily felt than seen—you might notice rough, dry, or scaly skin before you see any color change^[5].

Common characteristics include:

• Rough, dry, scaly, or crusty texture
• Discolored skin that may appear darker than your normal skin tone, or red, pink, brown, or gray
• Flat to slightly raised patches or bumps
• Usually less than 1 inch (2.5 centimeters) in diameter
• Itchy, tender, burning, or painful to the touch
• Bleeding or crusting in some cases

The patches typically appear on areas of your body frequently exposed to sunlight, such as your face, scalp, backs of your hands, forearms, ears, and neck^[5]. Some forms of actinic keratosis may look like dry skin or an acne breakout at first^[1]. You might mistake them for scabs or sores that won’t go away^[1].

A special type called actinic cheilitis affects the lower lip, causing dry, cracked, or white areas that may burn, peel, or not heal^[1]. The surrounding skin often shows other signs of sun damage, appearing blotchy, freckled, and wrinkled^[6].

Possible complications

The main concern with actinic keratosis is that it indicates an increased risk of developing skin cancer^[3]. While it’s rare for a single actinic keratosis to turn into cancer, the risk increases if you have multiple patches^[3].

Without treatment, there is a 5% to 10% risk that actinic keratosis will develop into squamous cell carcinoma, a type of skin cancer^[2]. If you have more than 10 actinic keratoses, the risk of squamous cell carcinoma occurring at some point is thought to be about 10 to 15%^[3].

Warning signs that an actinic keratosis may be developing into skin cancer include patches that become tender, thickened, ulcerated (develop an open sore), or start to enlarge^[3]. If you notice any of these changes—or if a patch begins to bleed, grows rapidly, or develops into a lump or horn—it’s important to seek medical advice promptly^[6].

Because they indicate sun-damaged skin, people with actinic keratoses are also at higher risk of developing other types of skin cancer, including basal cell carcinoma and melanoma^[3].

How is it diagnosed?

A primary care doctor or a dermatologist (a skin specialist) can usually diagnose actinic keratosis by examining your skin^[1]. The examination is quick and painless^[1]. Your doctor may use a special magnifying tool to get a better look at the affected areas^[1].

Sometimes, if there is any doubt about the diagnosis, your healthcare provider may need to take a small sample of your skin to send to a laboratory for testing^[1]. This procedure is called a skin biopsy^[2]. During a biopsy, a small sample of skin is removed after a numbing injection, and it can usually be done in a clinic^[2].

Even after treatment, your healthcare provider might suggest that you have your skin checked at least once a year for signs of skin cancer^[2].

Treatment options

Treatment is generally recommended for actinic keratosis because the patches are unsightly or uncomfortable, and because of the risk that skin cancer may develop^[3]. Although some actinic keratoses may go away without treatment, it’s hard to predict which ones will develop into skin cancer, so they’re usually removed as a precaution^[9].

Your treatment options depend on how many patches you have, where they are on your body, your age, and your overall health^[1]. Some individuals may choose not to treat actinic keratoses and simply monitor their skin regularly^[6].

Surgical procedures

If you have just a few isolated patches, your doctor may recommend removing them during an office visit^[1]. Common surgical options include:

• Cryotherapy (freezing): Your doctor applies liquid nitrogen to freeze the tissue, which eventually falls off, allowing healthy skin to emerge^[1]. The area may blister and peel off after a few days^[1]. It takes only a few minutes and can be done in your doctor’s office^[9].
• Curettage and desiccation: Your doctor scrapes or shaves off the patch, then uses heat or a chemical agent to destroy remaining cells and stop any bleeding^[1].
• Laser surgery: Your doctor applies a laser beam to vaporize the patch^[11].

Topical treatments

If you have numerous or widespread actinic keratoses, your doctor may prescribe creams or gels that you apply directly to affected areas of your skin^[11]. These medications can treat both visible and invisible patches with minimal risk of scarring^[11].

Approved topical medications include:

• 5-fluorouracil (available as Carac, Efudex, Fluoroplex)
• Imiquimod cream (Aldara, Zyclara)
• Diclofenac gel (Solaraze)
• Tirbanibulin (Klisyri)

These products may cause inflamed skin, scaling, or a burning sensation for a few weeks during treatment^[9]. During the treatment phase, the patches may become increasingly red and cause discomfort, and small patches you couldn’t see before may become visible^[1].

Photodynamic therapy

Photodynamic therapy (PDT) is a noninvasive treatment that uses a light-sensitive cream and special light to target actinic keratoses^[1]. It’s often used for multiple or recurring patches^[1]. This treatment is especially useful when you have many patches or when they’re in difficult-to-treat areas^[11].

Other treatments

Your doctor may also recommend a chemical peel, which involves applying a chemical to the skin that causes the top layers to peel off, allowing new skin to regrow within a few weeks^[11].

For areas that have become tender or painful, moisturizers can be used to help with scaly patches^[6].

How to prevent actinic keratosis

You can take important steps to stop actinic keratosis patches from developing or getting worse and to lower your chances of developing skin cancer^[1]:

• Use sunscreen with a sun protection factor (SPF) of at least 30 before going out in the sun and reapply regularly^[8]. Make sure to use a broad-spectrum sunscreen every day, even when it’s cloudy^[1].
• Wear a hat and clothing that fully covers your arms and legs when you’re out in the sun^[8].
• Avoid the sun between 11 a.m. and 3 p.m., which is when the sun is at its strongest^[8]. You should try to avoid sun exposure from 10 a.m. to 3 p.m. as much as possible^[1].
• Do not use sunlamps or sunbeds, as these can also damage your skin^[8].
• Do not sunbathe^[8].
• Check your skin regularly for any changes^[1].

If you always cover up outdoors due to actinic keratosis, consider taking 10 micrograms of vitamin D daily, as you may not get enough vitamin D from sunlight^[8].

Early diagnosis and sun protection can make a big difference in preventing actinic keratosis from turning into skin cancer^[1]. You should see a doctor if you notice new patches on your skin, if patches begin to bleed, get bigger, change color, feel tender, develop into a lump, or if a patch appears on your lips^[8].