Actinic Keratosis

Overview

Actinic keratosis is rough, scaly patches or spots that appear on skin that has been exposed to the sun for long periods. These patches are the result of damage to the skin from sun rays. They generally appear in sun-exposed areas such as the face, ears, lips, hands, forearms, scalp (especially in those with hair loss), and neck.

Actinic keratosis is also called "sun keratosis" or "solar keratosis." "Actinic" refers to sun rays; "keratosis" means thickening in the outer layer of the skin. These patches generally start small (no larger than a few millimeters) but can grow over time and merge together.

Actinic keratosis is not cancer, but the reason it is important is the risk of turning into cancer. If left untreated, approximately 5-10 percent of actinic keratoses can turn into squamous cell skin cancer over the years. For this reason, early diagnosis and treatment are important.

Actinic keratoses can be easily treated when detected early. Treatment options are very diverse and most are simple, effective, and can be applied in the office. Additionally, the formation of new lesions can largely be prevented with sun protection measures.

Actinic keratosis is especially common in fair-skinned people with blue or green eyes and blonde or red hair. It is prevalent in adults over 50; however, it can also be seen in young people with excessive sun exposure.

Symptoms

Actinic keratosis lesions generally develop slowly and may not be noticed initially. Since they are the result of sun damage spread over time, symptoms appear gradually.

Actinic keratosis symptoms include the following:

• Rough, coarse, or scaly patch. This is the most characteristic feature. When you touch the skin, it feels rough like sandpaper. The surface may be scaly, crusty, or like a thick crust. Sometimes it is felt when you run your finger over the skin without being visible.
• Color changes. Lesions are generally pink, red, or brown. Sometimes they are the same color as the skin and are noticed only by touch. They may appear as darker spots in dark-skinned people. Some lesions may be white or yellowish in color.
• Small size. Most actinic keratoses are between a few millimeters and 1-2 centimeters. However, if left untreated, they can grow or multiple lesions can merge to cover a wide area.
• Flat or slightly raised surface. Some lesions are flat, level with the skin; some are slightly raised. They can become more prominent over time.
• Hard, horn-like growths. Some actinic keratoses can develop as hard, conical protrusions called "cutaneous horns." These protrusions extend outward from the skin and can sometimes be several millimeters long. These types of lesions carry a higher cancer risk.
• Itching or burning sensation. Some lesions can create mild itching, burning, or tenderness. However, most are painless and do not cause discomfort.
• Recurring crusting and peeling. A crust may form on the lesion, peel off, and reddened skin may be visible underneath. Then crusting occurs again. This cycle repeats.
• White, scaly patches on the lip. Actinic keratosis seen especially on the lower lip is called "actinic cheilitis." It manifests as lip dryness, scaling, and whitish patches. It should be taken seriously because the risk of lip cancer is higher.

Actinic keratoses are generally seen in multiple areas and in large numbers. It is not unusual for a person to have dozens of lesions instead of a single lesion. This condition is called "actinic damage field"; meaning a wide area of skin has been affected by sun damage.

When to See a Doctor

Early detection of actinic keratoses is important. If you notice newly formed patches, rough areas, or non-healing sores on your skin, you need to see a doctor.

See a dermatologist in the following situations:

• If you have noticed a new, rough, or scaly patch on the skin
• If an existing spot is changing in color, size, or shape
• If there is a non-healing sore or recurring crust on the skin
• If a hard, horn-like protrusion has developed on your skin
• If there is a bleeding or painful lesion on the skin
• If you are over 50 and not having regular skin checkups
• If you have a history of intense sun exposure or sunburn in the past
• If you have previously been diagnosed with actinic keratosis or skin cancer

An annual skin examination is recommended:

Adults over 50, fair-skinned people, those who spend a lot of time in the sun, and those who have previously had actinic keratosis or skin cancer should have regular skin checkups. Early detection both facilitates treatment and reduces cancer risk.

Causes

The fundamental cause of actinic keratosis is prolonged exposure of the skin to sun rays. Ultraviolet (UV) radiation leads to DNA damage in skin cells and this damage accumulates over the years.

The process leading to actinic keratosis works as follows:

• UV radiation exposure. The sun's ultraviolet rays (especially UVB and UVA) damage cells in the outer layer of the skin. This damage is not seen immediately; it silently accumulates over years. Each sunbathing session, each sunburn increases this damage.
• DNA damage and cell changes. UV rays damage the DNA of skin cells. Normally the body repairs this damage or destroys damaged cells. However, as damage repeats and accumulates, some cells become abnormal and begin to multiply uncontrollably. These abnormal cells form actinic keratosis lesions.
• Cumulative sun damage. Actinic keratosis is generally the result of decades of sun exposure. The sun you got in your 20s and 30s can appear as actinic keratosis in your 50s and 60s. For this reason, sun protection measures in youth years are very important in the long term.
• Tanning bed use. Artificial tanning devices also emit powerful UV rays. Regular tanning bed use can cause as much or even more damage than natural sun and significantly increases actinic keratosis risk.
• Weakening of the immune system. The immune system weakens with age and struggles to clear damaged cells. Those taking immune-suppressing medications after organ transplant or those with diseases like HIV carry higher risk.

Risk Factors

Risk factors for actinic keratosis are as follows:

• Fair skin tone. This is the most important risk factor. Type I and Type II skin types (fair-skinned people who burn easily and don't tan or tan with difficulty) carry the highest risk. However, it can also be seen in dark-skinned people.
• Blonde or red hair. People with light-colored hair have less melanin (the pigment that protects the skin).
• Blue, green, or light-colored eyes. Light-eyed people generally have less melanin overall and are more sensitive to the sun.
• Advanced age. Actinic keratosis is generally seen over age 50 because UV damage accumulates over the years. However, it can also be seen in young adults with intense sun exposure.
• Intense sun exposure. People who work outdoors (farmers, construction workers, gardeners), those involved in outdoor sports, and those living in tropical regions are at higher risk.
• History of sunburn. Blistering sunburns experienced especially during childhood and youth significantly increase actinic keratosis risk.
• Tanning bed use. Regular artificial tanning use increases risk two to three times.
• Immune system suppression. Organ transplant patients, cancer patients receiving chemotherapy, or HIV patients carry higher risk.
• Having previously had actinic keratosis or skin cancer. In people who have developed actinic keratosis once, the likelihood of new lesions appearing is high.
• Hair loss or baldness. When the scalp loses its protective hair, it is directly exposed to the sun and the risk of developing actinic keratosis increases.
• Genetic predisposition. Some rare genetic diseases (such as albinism or xeroderma pigmentosum) make the skin extremely sensitive to UV damage.

Diagnosis

Actinic keratosis is generally diagnosed with clinical examination. An experienced dermatologist can make the diagnosis by looking at the appearance of the lesions. However, additional tests may be needed in some cases.

The methods used in the diagnosis of actinic keratosis are as follows:

• Physical examination. The dermatologist carefully examines your skin. The color, size, texture, and location of the lesions are evaluated. Roughness is felt by touching with the finger. A complete head-to-toe body examination is recommended because actinic keratoses are usually found in multiple areas.
• Dermatoscopy. This is a handheld magnifying glass and light device. It allows for more detailed examination by magnifying the skin surface. It helps distinguish between actinic keratosis and other skin lesions.
• Skin biopsy. When the diagnosis cannot be confirmed or if the lesion shows features that suggest cancer, a small tissue sample is taken. It is a simple procedure performed under local anesthesia. The tissue sample is examined under a microscope to make a definitive diagnosis and investigate the presence of cancer.
• Photography and follow-up. In some cases, photographs of the lesions are taken and followed over time to see if there is any change. This is especially useful in patients with numerous lesions.

It is important to distinguish actinic keratosis from basal cell carcinoma, squamous cell carcinoma, seborrheic keratosis, lentigo (age spot), and other benign skin lesions. An experienced dermatologist can generally make this distinction with examination.

Treatment

Actinic keratosis treatment has two basic goals: eliminating existing lesions and preventing cancer development. Treatment options are very diverse and are personalized according to the patient, the number of lesions, and their location.

The methods used in actinic keratosis treatment are as follows:

• Cryotherapy (freezing). This is the most commonly used treatment. The lesion is frozen and burned with liquid nitrogen. The procedure takes a few seconds and creates a mild stinging or burning sensation. A crust forms on the lesion and falls off within one to two weeks. It is simple, quick, and effective. It is preferred for small, few lesions. Temporary whitening (hypopigmentation) may remain on the skin after treatment.
• Topical chemotherapy creams. These are medication creams that destroy precancerous cells in the skin. 5-fluorouracil (5-FU), imiquimod, and ingenol mebutate are the most commonly used. They are generally preferred for numerous lesions spread over a wide area. The cream is applied once or twice daily for several weeks. During treatment, redness, itching, crusting, and burning sensation develop on the skin; this is a normal response and shows that the treatment is working. When treatment ends, the skin heals and improves.
• Photodynamic therapy (PDT). A light-sensitive medication is applied to the skin, then the lesion is stimulated with a special light. When light and medication combine, abnormal cells are destroyed. The procedure takes approximately one hour and generally requires two sessions. It is preferred in cosmetically important areas such as the face and scalp because it does not leave scars. Sun should be avoided for 48 hours after treatment.
• Curettage (scraping). The lesion is scraped out with a special spoon-like instrument. It is generally used for thick, raised lesions. Local anesthesia is required. A small scar may remain.
• Electrosurgery (burning with electricity). The lesion is burned and destroyed using electrical current. It can be applied together with curettage. Local anesthesia is required.
• Chemical peeling. The upper layer of the skin is peeled off with chemicals such as trichloroacetic acid (TCA). Actinic keratoses are also removed with this layer. It may be preferred in patients with widespread facial lesions. Temporary redness and peeling are seen on the skin.
• Laser therapy. The lesion is destroyed with laser beams. It is especially effective for lesions on the lip. General anesthesia is not required but local anesthesia may be applied.
• Surgical excision (cutting out). Rarely used. It is especially preferred for thick, suspicious-looking lesions or those with a high likelihood of being cancer. The lesion is completely removed and sent to pathology.

Treatment selection is made according to the number, size, and location of the lesions, the patient's preference, and the doctor's experience. In some patients, more than one method can be combined.

Complications

If actinic keratosis is left untreated or detected late, some complications can develop.

Complications of actinic keratosis are as follows:

• Squamous cell carcinoma (skin cancer). This is the most important and most feared complication. Approximately 5-10 percent of untreated actinic keratoses turn into skin cancer over the years. Squamous cell carcinoma can spread to other parts of the body and be life-threatening. If an actinic keratosis lesion is growing rapidly, bleeding, causing pain, or not healing, cancer may have developed.
• Cosmetic problems. Numerous lesions forming especially on the face can mar the skin's appearance. Redness, scaling, and color changes are aesthetically disturbing.
• Recurring infections. If the lesion is damaged due to scratching or rubbing, infection can develop. Crusting and wound formation provide grounds for bacterial entry.
• Treatment side effects. Some treatments can leave temporary redness, swelling, pain, or scars on the skin. However, most side effects are temporary and the treatment benefit outweighs these risks.
• Emergence of new lesions. Even if one actinic keratosis is treated, if sun damage continues, new lesions can form. For this reason, lifelong sun protection and regular skin checkups are essential.

Living with Actinic Keratosis

Receiving an actinic keratosis diagnosis can be worrying at first. However, knowing that cancer risk can largely be eliminated when these lesions are detected and treated early is reassuring. The basic principle of living with actinic keratosis is regular follow-up and sun protection.

Sun Protection: The Most Important Step

After being diagnosed with actinic keratosis, the most critical measure is sun protection. If sun damage continues, treated lesions can recur and new ones can appear.

• Use broad-spectrum sunscreen. Apply sunscreen with SPF 30 or higher every day, even on cloudy days. Choose "broad-spectrum" products that provide both UVA and UVB protection. Sunscreen should be part of your morning routine. Reapply every two hours, especially after swimming or sweating.
• Wear protective clothing. Long-sleeved shirts, long pants, and wide-brimmed hats provide the best protection from the sun. Clothing with UV protective properties can be preferred. If you have hair loss, use a hat or bandana.
• Stay in the shade. Especially between 10:00 AM-4:00 PM when sun rays are strongest, try to stay in the shade. Use an umbrella or awning when doing outdoor activities.
• Absolutely avoid tanning beds. Artificial tanning devices emit powerful UV rays and significantly increase actinic keratosis risk. Self-tanning creams are safe alternatives for a bronzed appearance.
• Protect your eyes. Wear sunglasses with UV protection. The delicate skin around the eyes should also be protected against UV damage.

Check Your Skin Regularly

Do your own skin examination once a month. Examine your entire body in the mirror, paying special attention to sun-exposed areas. If there are newly formed patches, changing spots, or non-healing sores, notify your dermatologist.

Ask your partner or family member to check your scalp, back, and areas you cannot reach. Regular self-examination increases the chance of early detection.

Regular Dermatologist Follow-up

After being diagnosed with actinic keratosis, go to a dermatologist checkup at least once a year. Your doctor examines your skin from head to toe, detects new lesions, and treats them if necessary. Those with numerous lesions or those at high risk of cancer may require more frequent checkups (every 6 months or every 3 months).

Don't skip checkup appointments. While actinic keratoses detected early can be treated with simple methods, late detection can lead to cancer development.

Post-Treatment Care

Your skin may be sensitive after treatment. Follow the care instructions your doctor recommends. Generally, using moisturizer, keeping the wound dry, and avoiding sun are recommended.

Temporary redness, crusting, and tenderness on the skin after cryotherapy or topical cream treatment are normal. These symptoms disappear within a few weeks. However, if there is increasing pain, fever, or signs of inflammation, notify your doctor.

Lifestyle Changes

A healthy immune system helps the skin repair itself. Eat a balanced diet, exercise regularly, quit smoking, and manage stress. Consume vegetables and fruits rich in antioxidants; these support skin health.

Sleep adequately. During sleep, the body accelerates cell repair. 7-8 hours of quality sleep at night contributes to both your general health and your skin health.

Create Awareness in the Family

Actinic keratosis is not a condition with genetic predisposition, but family members may have similar skin type and sun exposure. Especially teach your children and young family members the importance of sun protection. Protection started at an early age greatly reduces the risk of actinic keratosis and skin cancer in the future.

Preparing for Your Appointment

What you can do:

• Note the changes you have noticed on your skin and when they started
• Photograph your lesions so you can track changes over time
• List all medications, creams, and supplements you use
• Mention any skin cancer or actinic keratosis treatments you have had before
• Prepare your sun exposure history (your occupation, hobbies, tanning bed use)
• Report if there is a family history of skin cancer
• Write your questions down in advance

Questions you can ask your doctor are as follows:

• Are these lesions definitely actinic keratosis or could it be something else?
• What is my cancer risk?
• What is the most appropriate treatment option for me?
• How long will treatment take and what are the side effects?
• How often should I have checkups?
• How can I prevent new lesions from forming?
• Which sunscreen is most appropriate?
• Should I have my family checked as well?

Questions your doctor may ask you are as follows:

• When did you notice these lesions?
• Are they changing, growing?
• Is there itching, bleeding, or pain?
• Have you had skin cancer or actinic keratosis treatment before?
• What is your occupation, do you spend a lot of time outdoors?
• Do you use sunscreen regularly?
• Have you had sunburn in the past?
• Have you used or do you use tanning beds?
• Is there a family history of skin cancer?