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How are precancerous skin spots (Actinic Keratosis) treated?

Updated: May 19, 2023


Disclaimer: The information in this article is not meant as specific individual medical advice. Please consult your dermatologist or other medical professional about your skin or medical condition.


What is a pre-cancerous skin growth (Actinic Keratosis)?

Actinic keratosis (AK) is considered a pre-cancerous skin growth.

A pre-cancerous skin growth is a term to describe a skin lesion that has a higher risk of becoming a skin cancer.

Specifically, an actinic keratosis can develop into squamous cell carcinoma, which is a common type of skin cancer.

The difference between a pre-cancerous actinic keratosis and a skin cancer is that a skin cancer has the ability to invade and destroy healthy tissue and even acquire the ability to spread to other organs in the body, whereas an actinic keratosis does not.

What does an actinic keratosis look like?

According to the Skin Cancer Foundation, as many as 58 million Americans have one or more actinic keratoses.

Actinic keratoses appear as small pink dry scaly crusty rough spots that you may sometimes feel better with your hands than see with your eyes.

They may sometimes look like a small horn.

Actinic keratoses tend to form in areas of sun exposure such as the scalp, face, ears, neck, hands, arms and legs.

They can form as individual lesions or as several lesions affected an entire area of skin.

What causes pre-cancerous actinic keratosis to form?

Actinic keratosis form as a result of frequent exposure to harmful ultraviolet (UV) radiation from sun exposure, sun burns or indoor tanning.

UV radiation causes DNA damage to skin cells which lead to genetic mutations.

Actinic keratosis forms when enough DNA damage has been accumulated in the skin cells.

As more genetic mutations accumulate with further DNA damage, AKs become skin cancers.

Who are at risk of developing pre-cancerous actinic keratosis?

People who are frequently exposed to harmful UV radiation from the sun, sunburns or indoor tanning are at an increased risk of developing AKs.

People with naturally fair skin are also at an increased risk, especially if working outdoors or living geographically close to the equator.

Medications or medical conditions that suppresses the immune system, such as medications used in organ transplant, may also increase the risk of AKs forming.

How is actinic keratosis diagnosed?

Actinic keratosis are typically diagnosed on examination by your dermatologist.

Occasionally, your dermatologist may take a skin biopsy of a larger lesion that looks suspicious for a skin cancer, and it turns out to be a pre-cancerous AK.

Treatment of actinic keratosis

Actinic keratosis can be treated in a few ways:

  • Cryosurgery

  • Topical medication

  • Photodynamic therapy

  • Chemical peel

  • Laser surgery


Cryosurgery is a procedure where your dermatologist applies liquid nitrogen on the AK.

Liquid nitrogen freezes the tissue, causing the AK to blister, dry into scab and eventually fall off.

New healthy skin then heals over to replace the treated area.

This is one of the most commonly used treatments for AKs.

It is also common for multiple lesions to be treated at a single visit.

Topical medications

There are a few topical medications that can be used to treat AKs.

These topical treatments include:

  • 5-fluorouracil (Efudex®, Carac®)

  • Imiquimod (Aldara®, Zyclara®)

  • Ingenol mebutate (Picato®)

  • Diclofenac (Solaraze®)

These topical treatments are usually used when a person has numerous AKs in one area, or widespread AKs over different parts of the skin.

The treatments are meant to be applied to the skin for a fixed amount of time (between a few days and up to 4-6 weeks at a time) and discontinued.

Through your immune system, these treatments cause inflammation to develop in the areas where they are applied.

That means the treated skin becomes red, swollen and painful. Blistering and oozing may also occur.

After the treatment is completed, it typically takes another two to four weeks for the inflammation to resolve and for the AKs to peel off.

These treatments may be repeated more than once to treat AKs that are more resistant.

Occasionally, your dermatologist may combine the use of cryosurgery with topical treatments to target the more persistent lesions.

Photodynamic therapy (PDT)

Photodynamic therapy or PDT is an in-office light treatment that is effective in removing AKs.

This involves applying a light-sensitizing agent called aminolevulinic acid (ALA) to the areas that are to be treated.

ALA is allowed to sit on the skin for a period of time between 30 minutes and 2 hours.

This is followed by an exposure to a lamp that emits blue or red light.

Pre-cancerous selectively absorb more ALA than normal tissue, and absorb more light energy.

This process causes the pre-cancerous cells to be targeted while healthy tissue is not harmed.

During the treatment, it is common to feel a burning sensation during the period of light exposure.

This is followed by inflammation (redness and pain) involving the treated skin for about 1 week, which resolves on its own.

ALA also causes the treated skin to be sensitive to sunlight for a period of up to 3 days. This means that you want to take extra sun protective precautions during those days if you are undergoing this treatment to avoid getting burned by the sun.

PDT is most commonly used to treat AKs on the scalp and face, and may also be used for AKs on the forearms, legs or upper back.

Occasionally, your dermatologist may combine the use of cryosurgery with PDT to treat the more persistent lesions.

Other treatments for actinic keratosis

Chemical peel and laser surgery may also be used to treat actinic keratosis, although less commonly.

Chemical peel is usually used to treat actinic keratosis on the face.

It involves applying a chemical, such as trichloroacetic acid (TCA) to the face which then causes the top layer of the skin (epidermis) to peel off.

New healthy skin that regrows over a few weeks to replace the previously sun damaged skin.

Laser surgery involves using an ablative laser to vaporize individual AKs.

Skin cancer prevention

Avoiding excessive sun exposure, and taking sun protective precautions is the main preventive action people can take to reduce their risk of developing actinic keratosis and skin cancer.

These protective measures include:

  • Seeking shade especially when the sun’s rays are the strongest between 10am and 2pm.

  • Wearing sun-protective clothing such as sunglasses, wide-brimmed hat, and long-sleeved cloths. Certain sun protective clothing has a UPF (ultraviolet protection factor) label.

  • Applying a broad-spectrum water resistant sun screen with SPF 30 or higher

  • Reapplying sun screen every two hours

  • Avoiding use of indoor tanning beds

An annual skin cancer screening by your dermatologist can help with detecting skin cancer early.

When found early, skin cancers are mostly curable.

In addition, it is recommended that people perform self-skin exams once a month to look for suspicious spots or unusual looking moles.

I hope this article has been helpful in informing you about pre-cancerous skin growths, actinic keratosis and their treatment options. I hope this information will empower you when you make your medical decisions with your dermatologist.

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