Actinic Keratosis (AK)
Published on October 3, 2024
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Actinic keratosis (AK), also called solar keratosis, is a skin lesion that’s caused by ultraviolet (UV) damage. It looks like a rough, scaly patch or bump on the skin. If it’s not treated, an AK can sometimes turn into skin cancer.
Overview
What Is Actinic Keratosis?
Actinic keratosis (AK) is a rough scaly patch that forms on your skin due to chronic UV exposure. An AK usually shows up on areas of the body that are frequently exposed to the sun, such as your face, ears, lips, scalp, neck, shoulders, and hands. If you develop more than one actinic keratosis lesion, you are said to have actinic keratoses (AKs; plural).
If you don’t treat AKs, they can turn into a type of skin cancer called squamous cell carcinoma. But only about 5 to 10 percent of AKs will turn into cancer. Most of the time, an AK goes away with treatment, but since doctors don’t know which AKs will turn into skin cancer, it’s important to treat them all.
Signs and Symptoms of Actinic Keratosis
AKs usually develop slowly on sun-exposed areas of the skin. They can vary in appearance but generally show up as rough, raised bumps or patches of skin. These lesions may be gray, pink, red, or flesh-toned with a yellow or brown crust on top. They’re usually less than 1 inch in diameter.
Other symptoms of an AK lesion include:
- Itching, burning, or stinging areas of skin
- Bleeding or crusting of the skin
- Dry, scaly patches of skin
- Loss of color in the lips
- Pain or tenderness on areas of the skin
- Hard, horn-like, or wart-like growths
Causes and Risk Factors of Actinic Keratosis
The main cause of AK is exposure to too much UV light. Over time, UV rays from the sun or indoor tanning devices can damage the cells in the outer layer of your skin, which are called keratinocytes. This results in an AK lesion.
While anyone can develop AKs, you are at an increased risk if you:
- Have fair skin, blue or green eyes, or blond or red hair
- Work outside or spend a lot of time in the sun
- Live in a sunny area
- Burn or freckle easily
- Have a history of sunburns or excessive sun exposure
- Are older than 40
- Have a weakened immune system
- Had an organ transplant
- Take medicines that suppress your immune system
How Is Actinic Keratosis Diagnosed?
Most of the time, doctors can diagnose an AK by visually examining and feeling the lesion. If they are unsure whether the spot is an AK, they may perform a skin biopsy. This involves cutting out a small piece of tissue and sending it to a lab to be examined under a microscope. Results of the biopsy can confirm a diagnosis.
A dermatologist (a doctor who specializes in skin conditions) usually diagnoses AKs.
Treatment and Medication Options for Actinic Keratosis
Doctors don’t know which AKs are harmless and which will turn into cancer. That’s why treating the lesions is important. There are several different treatment options available. Your doctor can help you decide which therapy is best for your condition.
Medication Options
Topical gels or creams are sometimes prescribed to remove AKs. These may include the following medicines:
- fluorouracil (5-FU) This cream blocks the growth of abnormal cells.
- imiquimod (Aldara) This treatment prompts your immune system to fight off the precancerous lesions.
- diclofenac This medicine is a nonsteroidal anti-inflammatory drug (NSAID) and is usually less irritating than other topical treatments, but it must be used for a longer period of time.
- tirbanibulin (Klisyri) This newer medicine works by killing abnormal cells. It’s usually applied for five days.
These topical therapies can be applied at home. You may have to use them for up to four months, depending on the severity of your AK and the specific medicine. Possible side effects include red, inflamed, sore, burning, or scaling skin where the medicine is applied.
Cryotherapy
With cryotherapy, doctors use liquid nitrogen to freeze the AK lesions. The spots will blister and fall off a few days later. Cryotherapy is the most common treatment option for AK. It can be done in your doctor’s office. Possible side effects include blistering skin, changes in skin color or texture, infection, and scarring.
Surgery
Sometimes, doctors will remove the AK lesion via a simple excision procedure. They will first numb your skin around the AK. Then, your provider will scrape away or cut out the AK. The area will be stitched back together. It typically takes about two to three weeks for the wound to heal.
Laser Therapy
Your doctor may use an ablative laser device to destroy your AK patches, and new skin will grow in its place. Lasers can cause side effects, such as scarring and discolored skin.
Photodynamic Therapy
Photodynamic therapy is often used when a person has multiple AKs or AKs that come back after initial treatment. It involves using a light-sensitive cream to the affected area and exposing it to a special light that destroys the AK. Side effects may include swelling, inflamed skin, and a burning sensation during the treatment.
Chemical Peel
Sometimes, doctors will recommend a chemical peel to treat AKs. Special substances in the peel destroy precancerous lesions in the top layer of your skin. As your skin heals, a new healthy layer of skin surfaces. The peel can be applied during an office visit.
Prevention of Actinic Keratosis
Sun safety measures can help prevent AKs. Here are some steps to take:
- Avoid too much sun. Try not to go outdoors between 10 a.m. and 2 p.m. if you can. Also, don’t stay in the sun long enough to tan or get a sunburn.
- Use sunscreen. Apply sunscreen with a sun protection factor (SPF) of at least 30 when you are outdoors, even on cloudy days. Be sure to put it on at least 15 minutes before you go outside and reapply every two hours.
- Wear protective clothing. Clothes that cover your arms and legs and large, broad-brimmed hats can help protect your skin from the sun’s harmful rays.
- Don’t use tanning beds. The UV light you’re exposed to in tanning beds can cause just as much damage as the sun.
- Check your skin often. Look at your skin for new moles, bumps, freckles, or other spots. Be sure to report any skin changes to your doctor.
- Have regular skin exams. A dermatologist can help you spot any abnormal skin lesions early, when they are most treatable.
How Long Does an Actinic Keratosis Last?
After treatment, it can take up to three months for an AK to completely go away. Once the lesion fully disappears, you will likely need to see your doctor for a follow-up visit once or twice a year. If you have a weakened immune system, your doctor may want to see you four to six times a year. Most AKs can be successfully treated. But they can return if you don’t take measures to prevent future sun damage.
Complications of Actinic Keratosis
If untreated, AK can turn into squamous cell carcinoma. This only happens in about 5 percent to 10 percent of AK cases, but most squamous cell carcinomas start as AKs.
Squamous cell carcinoma is the second most common form of skin cancer. When it’s caught and treated early, it’s usually curable.
Research and Statistics: Who Has Actinic Keratosis?
AK is the most common skin precancer. About 58 million people in the United States have one or more AKs. Each year, more than 40 million Americans develop AKs.
Men are slightly more likely to develop AKs than women. Experts theorize that this is because men are less likely to use sun protection.
Related Conditions
Some conditions that are closely related to AK include:
- Squamous cell carcinoma: A type of skin cancer that starts in the cells in the outside layer of your skin.
- Bowen disease: This is a very early form of squamous cell carcinoma.
- Basal cell carcinoma: This skin cancer forms in the basal cells, which are found in the lower part of the outside layer of your skin.
- Actinic cheilitis: This is a precancerous condition that affects the lips and is caused by lots of sun exposure.
- Merkel cell carcinoma: This is a rare but aggressive type of skin cancer that affects the Merkel cells, in the outer layers of your skin.
- Melanoma: This type of skin cancer forms in cells called melanocytes. Melanoma is the most serious form of skin cancer.
The Takeaway
Actinic keratosis is a common skin condition that, if ignored, could turn into skin cancer. If you catch it early, AK can be successfully treated. See your doctor if you have rough, scaly patches of skin that you think might be AK.
Resources We Trust
- Cleveland Clinic: Actinic Keratosis
- Mayo Clinic: Actinic Keratosis
- Skin Foundation: Actinic Keratosis
- American Academy of Dermatology Association: Actinic Keratosis: Overview
- American Cancer Society: Treating Actinic Keratosis and Bowen Disease
Common Questions & Answers
What is the best treatment for actinic keratosis?
Treatment for AK may involve different topical medications (creams or gels you put on the skin), surgery, chemical peels, cryotherapy, light therapy, or laser procedures. Your doctor can help you decide what therapy would be the best option for your particular case.
What happens if actinic keratosis is left untreated?
If an AK is left untreated, it could turn into a type of skin cancer called squamous cell carcinoma.
How commonly does actinic keratosis turns into cancer?
In about 5 percent to 10 percent of cases, an AK turns into skin cancer.
Can actinic keratosis go away?
AKs sometimes disappear on their own. But they could return after more sun exposure. It’s important to seek treatment because doctors don’t know which AKs will go away spontaneously and which will develop into skin cancer.
Meet Our Experts
Jacquelyn Dosal, MD
Medical Reviewer
Jacquelyn Dosal, MD, is a board-certified dermatologist at Skin Associates of South Florida in Coral Gables. She practices general, medical, cosmetic, and surgical dermatology.
Dr. Dosal provides compassionate care to all her patients, listening to their concerns and creating a treatment plan with each patient's priorities and real life in mind.
She is a member of the voluntary faculty at the University of Miami.
Julie Lynn Marks
Author
Julie Marks is a freelance writer with more than 20 years of experience covering health, lifestyle, and science topics. In addition to writing for Everyday Health, her work has been featured in WebMD, SELF, Healthline, A&E, Psych Central, Verywell Health, and more. Her goal is to compose helpful articles that readers can easily understand and use to improve their well-being. She is passionate about healthy living and delivering important medical information through her writing.
Prior to her freelance career, Marks was a supervising producer of medical programming for Ivanhoe Broadcast News. She is a Telly award winner and Freddie award finalist. When she’s not writing, she enjoys spending time with her husband and four children, traveling, and cheering on the UCF Knights.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
- Actinic Keratosis Overview. Skin Cancer Foundation. September 2024.
- Actinic Keratosis. Cleveland Clinic. December 4, 2020.
- Actinic Keratosis. Mayo Clinic. December 17, 2022.
- Actinic Keratosis. MedlinePlus. November 18, 2022.
- Actinic Keratosis (AK). Yale Medicine.
- Tirbanibulin Topical. MedlinePlus. March 15, 2021.
- 5 Facts You Should Know About Precancerous Skin Growths. American Academy of Dermatology Association. July 17, 2023.
- Squamous Cell Carcinoma: Overview. Skin Cancer Foundation. March 2023.
- Actinic Keratosis: Overview. American Academy of Dermatology Association.
- Skin Cancer. Cleveland Clinic. November 19, 2021.
- Treating Actinic Keratosis and Bowen Disease. American Cancer Society. October 31, 2023.
- Actinic Cheilitis. Cleveland Clinic. May 13, 2022.
- Merkel Cell Carcinoma. Cleveland Clinic. April 15, 2022.