Actinic keratoses: What are they and how to eliminate them?

The skin has a memory and all the sun that we accumulate during our lives will manifest itself at some point (it will take its toll). One of the consequences of having accumulated too much UV radiation is actinic keratoses. While we consider actinic keratoses to be benign, we know that 5-10% will develop into skin cancer in our lifetime. That is why it is best to play it safe and see a dermatologist if you think you may have an actinic keratosis. 

In this article I will explain in more detail what actinic keratoses are and how we can treat them. First, let me tell you something about myself: I am currently working at the Hospital Clínic in Barcelona where I have highly specialized experience in the diagnosis and treatment of skin cancer and pre-malignant lesions such as actinic keratoses. 


What will I talk about in this article?

What are actinic keratoses?

Actinic keratosis is an abnormal proliferation of cells in the epidermis (outermost layer of the skin) caused by long-term sun damage. They are not malignant, but a small fraction of them will develop into skin cancer. As we do not know which ones will turn into cancer and which ones will not, dermatologists recommend treatment of these lesions. 

Actinic keratoses are precancerous changes in skin cells (keratinocytes) that are a frequent consequence of many years of sun exposure.

Depending on the country we live in (sun exposure) the prevalence of actinic keratoses can be very high. For example, in Australia we see that approximately 10% in people in their 20s and 30s and over 90% in people over the age of 80 will have this condition. In fact, some studies suggest that virtually everyone will eventually develop actinic keratoses as they age.

Illustration showing the progression of actinic keratoses to skin cancer.

Here we can see the progression of the damage we generate in our skin as we accumulate ultraviolet radiation. First of all, mutations will accumulate in our DNA that after a few years will end up developing an actinic keratosis. If we do not treat these actinic keratoses they can evolve into a squamous cell carcinoma of the skin (skin cancer).

What are the risk factors for developing actinic keratoses?

UV radiation exposure accumulated over the years is primarily responsible for the development of actinic keratosis.It is therefore more frequent in older people. Quote

This accumulation occurs when sunbathing and there are people who will present them more frequently, such as: Quote

  • Having red or blond hair and blue or light eyes
  • Having a history of heavy sun exposure or sunburns
  • Freckling or burning when exposed to sunlight
  • Over 40 years of age
  • Living in a sunny location
  • Working outdoors
  • Having a weakened immune system
  • Users of tanning booths, especially during adolescence. 

It is true that, although sunbathing has certain beneficial effects, for example, sunlight is necessary for the skin to produce vitamin D, however, excessive exposure to ultraviolet light also causes mutations in the DNA of our skin cells. This favors premature photo-aging, the development of actinic keratoses and skin cancer.

Nowadays there are many myths about sunbathing for vitamin D production and I have made a whole article here in order to clarify how much sun is really needed to produce this vitamin. 

Photos of actinic keratosis

Actinic keratoses are usually easier to touch than to see. The skin may feel dry and rough to the touch, or raw, tender and painful, or even with an itching or burning sensation. 

Rarely, they may bleed or develop a persistent wound, also known as erosion. In other cases, they appear and disappear in the same place recurrently. 

As they are produced by chronic sun exposure, they will be more frequently observed on the face, ears, lips, bald scalp, forearms, backs of the hands and lower legs.

Actinic keratosis on a patient's nose

Photo of a patient with a single actinic keratosis on the nasal ala. In this case local treatment was required in order to completely eliminate the lesion. 

Multiple actinic keratoses on the scalp of a patient with chronic sun damage

Photo of a patient with multiple actinic keratoses on the scalp who had worked outdoors and had been exposed to the sun throughout his life. 

Photos of a patient with chronic actinic damage and multiple actinic keratoses.

Photos of actinic keratosis in a patient with a lot of photodamage. When we accumulate UV radiation on our skin it will manifest itself with different lesions. In the photo we can see several manifestations of this photodamage such as actinic keratoses, the solar lentigines or hypopigmentation.

What is the importance of having actinic keratoses?

Early detection of an actinic keratosis makes it possible to treat the lesion and prevent skin cancer before it appears. When diagnosed early, almost all actinic keratoses can be treated successfully. The problem is that, if left untreated, some actinic keratoses can progress to skin cancer. 

During the life of a 5-10% of actinic keratoses can develop into skin cancer. That is why it is better to play it safe and see a dermatologist if you think you may have actinic keratoses.

Treatment of actinic keratoses

It is very important to identify and treat actinic keratosis lesions to reduce the progression of the disease to skin cancer. The number of lesions is one of the factors we will take into account in the choice of treatment. Although we will always take into account other factors such as your age, the adverse effects of the treatment and the preferences of each patient.

Once in the office we will choose between several types of treatment, but basically we can classify them as those that destroy single lesions or treatment that treat an entire area affected with many actinic keratoses, i.e. the cancerization field. 

  • In patients presenting few actinic keratoses we prefer to treat individual lesions.
  • In patients with many lesions and a lot of sun damage in the skin we are more inclined to treat all affected skin. 

1- Local destructive treatment

In mild cases in which the patient has isolated actinic keratoses we will choose a treatment that allows us to treat these lesions in isolation. The most common way to do this is by freezing therapy or cryotherapy which is with liquid nitrogen. This causes a kind of localized freezing and after one or two days, the spot will develop a crust or a small blister, which will fall off and heal within four to six weeks.

2- Treatment of all photodamaged skin

When there are multiple lesions (for example, on the scalp of bald men who spend a lot of time in the sun without wearing a hat), the use of liquid nitrogen does not make sense. When there are many, it does not make sense to remove them all individually. It is much more effective to apply a field treatment over a wide area. This removes the spots that are visible and also prevents new ones from growing.

In these situations there are several options. Among them we can prescribe a cream to apply regularly at home or we can also do in-office treatment such as photodynamic therapy. Let's quickly review the treatment creams that we can do:

  • Fluorouracil cream: The most commonly prescribed cream is fluorouracil, also known as 5-FU. It works by blocking the growth of the abnormal cells that cause the skin disease. It is usually applied once or twice a day for two to six weeks and causes irritation, redness and pain (a moisturizing lotion or petroleum jelly can help soothe the area). The short-term discomfort during medication use is a price worth paying for the long-term benefit of fewer skin lesions. In addition, we now have strong clinical evidence that topical fluorouracil treatment can decrease the rate of future skin cancers in high-risk patients.Quote
  • Imiquimod cream: It is a type of immunotherapy that helps the patient's immune system fight precancerous lesions. Although imiquimod creams work through a different process than fluorouracil, their results are similar: redness and irritation that eventually heal to reveal new, smooth skin.
  • Diclofenac gel: This anti-inflammatory gel is less irritating than other creams, but it is also much less popular. It has to be used for a prolonged period of time and does not have as effective an effect as other topical creams.
  • Tirbanibulin 1%: is a new cream treatment that is available in Spain from 2022. It requires a 5-day consecutive application period and is effective, demonstrating complete elimination (100%) of actinic keratosis lesions in 49% of patients, partial elimination (>75%) in 72%.Quote
On the other hand, there are also very effective treatments that we can use in our practice for the treatment of actinic keratoses.
  • Photodynamic therapy with light: Multiple lesions can also be treated with photodynamic light therapy, which involves applying a liquid medication called a photosensitizer to the skin. The medication is then activated with a special blue or red light to kill the abnormal skin cells. Patients may experience some tingling or even burning during treatment at the doctor's office. For several days after treatment, the skin will appear reddened and sometimes scaly, similar to a sunburn. Photodynamic therapy is usually not as irritating as cream treatments and is equally effective in treating multiple lesions. 

Can actinic keratoses be prevented?

The answer is yes, and there are 2 different types of prevention.

  1. Primary prevention which refers to preventing actinic keratoses before they appear for the first time.
  2. Secondary prevention, which refers to the prevention of actinic keratoses from reappearing once they have been treated.

1- Primary prevention of actinic keratosis

To prevent the appearance of seborrheic keratoses and to have healthy skin, it is necessary to have an effective sun protection strategy since childhood. In this way we can reduce the risk of developing actinic keratoses, photodamage, skin aging and finally skin cancer. Here are my recommendations for photoprotection. Quote
  • Avoid exposure to unprotected UV rays.
  • Seek shade, especially between 10 am and 4 pm,
  • Use a broad spectrum sunscreen (UVA and UVB).
  • Wear sun-protective clothing, a wide-brimmed hat and sunglasses with UV filters.
  • Avoid UV rays from tanning booths. Exposure to UV rays from a tanning bed can cause as much or more damage to the skin than a tan acquired in the sun.Quote
  • Check your skin regularly and report any suspicious changes to your dermatologist. Examine your skin regularly, looking for the development of new skin growths or changes in existing moles, freckles, bumps and birthmarks. With the aid of mirrors, check your face, neck, ears and scalp. Examine your upper and lower arms and hands.
 For more information on how to protect yourself from the sun you can read this article dedicated to the subject with many recommendations from me. 

2- Secondary prevention of actinic keratosis

In addition to having actinic keratoses, many of my patients have multiple skin cancers. The most important thing is still to avoid the sun and use sunscreen regularly. However, we can also do more to prevent non-melanoma skin cancer and decrease the number of actinic keratoses. 

We have plenty of evidence of other treatments that may reduce the risk of developing further skin cancers.

Nicotinamide or Vitamin B3 has been shown to significantly reduce the risk of developing the milder skin cancers of basal cell carcinoma, squamous cell carcinoma and even reduce the precancerous lesions of actinic keratosis.

Illustration of nicotinamide or vitamin B3 for the prevention of actinic keratoses and non-melanoma skin cancer.

Taking 500 mg of vitamin B3 twice a day can reduce the risk of developing skin cancers by up to 30%. In Spain you can find it under the name of Photoprevent B3 at the following link. 

I usually recommend vitamin B3 to my patients after their first non-melanoma skin cancer and in patients who have a lot of sun damage (actinic damage), because at that stage they are very likely to develop many more over time.

Final words on actinic keratoses

If you have actinic keratoses, it is important to visit your dermatologist every year for a professional skin examination. Having a specialist who is an expert in the identification and treatment of this type of skin lesions is essential for your health and well-being. Anyone with actinic keratoses should be under the care of a dermatologist.

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Sebastian Podlipnik - Skin cancer

Sebastian Podlipnik

Dermatology Blog

I am a dermatologist and cum laude MD and author of multiple research studies. I specialize in skin cancer, laser technologies and cosmetic dermatology. The intention of this blog is to bring you closer to topics of interest in dermatology and research.

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