Actinic keratosis (AK) is sun-damaged skin, literally meaning skin keratinization caused by the sun. AK is a chronic excess of ultraviolet radiation on sun-exposed skin areas. Often found on the scalp (bald head), auricles, nose, backs of the hands, lips in men and on the décolleté, face, lower legs and arms in women.
Who is more at risk for actinic keratosis?
AK is common (in 11-25% of people over 40 years old). People with a white skin type (blonde or red hair and blue eyes) are especially vulnerable. We also see more younger people with these abnormalities. This may be related to changed leisure activities, due to sun vacations, tanning beds, incorrect sunscreen application technique (more on sunscreen application), spots on the skin that are often forgotten to apply sunscreen (more on forgotten spots).
Risk groups are people who work outdoors (farmers, exterior painters, gardeners, sailors), water sports enthusiasts, expats who have lived in the tropics for a long time, and people who use immunosuppressive drugs (prednisone, azathioprine, ciclosporin, methotrexate, cytostatics) for a long time.
It is estimated that as they age up to 80% of this group of people will develop an AK.
The number of patients with AK in the Netherlands is increasing due to the aging population and increasing exposure to sunlight.
Actinic keratosis – dental plaque of the skin
AK is a cornification and maturation disorder of the skin due to prolonged exposure to ultraviolet light. The cornification disorder is caused by DNA damage in the epidermis. AK is considered a precancerous stage of skin cancer.
Most people know what dental plaque is and that dental problems will eventually arise if you don’t remove it by brushing and flossing daily.
AK can do no harm in the short term, just like plaque on your teeth. But in the longer term, AK can degenerate into squamous carcinoma. Squamous cell carcinoma is malignant and is one of the three most common skin cancers. This type of skin cancer originates in the top layer of skin (epidermis) and can sometimes spread to lymph nodes and other organs.
The 10-year incremental risk of developing squamous cell carcinoma in patients with AK is estimated to be approximately 10% (range 6-16%). The relative risk (RR) of developing squamous cell carcinoma also increases with the number of AK spots on the skin. People with less than 5 AK have an RR of about 1%. If you have more than twenty AK, the risk increases to 20%. And conversely, 50-60% of squamous cell carcinomas probably arise from AK.
The general advice is to identify and treat these skin lesions before they become malignant.
How do you recognize it?
They are small, often rough-feeling keratinized spots of the skin. They have a texture of sandpaper or a grain of sand. The color varies from skin-colored to red and yellow-brown. The size can vary from a few millimeters to a few centimeters. Preferred places are the sunlit skin areas.
The spots tend to bleed easily, especially after drying after washing or rubbing your face. Sometimes it can be itchy and also mildly painful when touched.
Treatments at the dermatologist
Treatment of AK makes sense because of the risk of developing skin cancer. And you can’t predict which AK spot on the skin will degenerate.
Dermatologists have a few treatment methods. The choice of treatment depends on the size, extent and localization of the skin lesions.
The most commonly used methods are:
Liquid nitrogen treatment, freezing of some visible or tangible rough spots is a very efficient method.
Use of ointments such as Efudix cream. It contains the active substance fluorouracil, which reacts specifically to the cells that are abnormal and grow too quickly. It first cleans up these cells and then healthy skin cells take their place. The effect of Efudix is only aimed at the abnormal sun-damaged cells, but it leaves healthy skin relatively alone.
Aldara cream, active ingredient: imiquimod 5%. This is an immune-modulating agent that is applied three times a week for 4 to 6 weeks. Imiquimod activates the immune system locally in the skin, which clears up the basal cell carcinoma. During treatment with imiquimod cream, redness and crusting (a kind of abrasion) may develop. Then healthy skin will return. Sometimes people can develop flu-like symptoms and skin inflammatory reactions occur.
Photodynamic therapy (PDT). A cream containing a light-sensitive substance (methyl aminolevulinic acid (MAL) or 5-aminolevulinic acid (ALA) is applied to the spot or spots. This cream makes the malignant cells more sensitive to light. After an exposure period of several hours, the skin defect is illuminated with a special lamp. A reaction then takes place in the exposed skin part or skin parts, causing the cancer cells to perish. It is quite a painful treatment and sometimes it needs local anesthesia.
Furthermore, a dermatologist can decide to excise it, such as with large and therapy-resistant spots, curette, CO2 fraxella laser and chemical peels with, for example, trichloroacetic acid.
What can you do yourself
Vitamin A products such as tretinoid are a powerful and effective option to reduce existing sun damage. The over-the-counter option is retinol, which is available in different concentrations and formulations. The efficacy of retinol is already at 0.3%. A higher concentration is not always better, it can cause skin irritation and more absorption in the body. For skin problems such as reduction of fine lines, removal of the epidermis and a more even complexion.
Vitamine B3 (Niacinamide):
Niacinamide, one of the eight B vitamins, is the so-called essential vitamins. This means that only a small part can be stored in our body.
Niacinamide can reduce the risk of skin cancer! An Australian study has shown that the topical use of niacinamide can have a reduction in actinic keratosis. A 1% niacinamide ointment was used in the study. Even low doses of UV radiation can cause measurable DNA damage in the skin. Niacinamide is able to improve this recovery and reduces the suppression of the skin’s immune reactions caused by UV radiation.
Iconic Elements Spotreducer and Targeted Pigment serum contain >1% niacinamide.
More studies (in vitro) showing that blueberries prevent carcinogenesis include inhibition of the production of pro-inflammatory molecules, oxidative stress (free radicals), and consequences of oxidative stress such as DNA damage, inhibition of cancer cell proliferation, and increased apoptosis. This causes tumor cells to perish earlier. Blueberries also have a protective effect against skin cancer for the skin.
Lycopene, abundant in tomato paste
It has been shown that a diet rich in fruits and vegetables can provide overall protection against these skin cancers. Some studies showed that certain nutrients reduced some of the effects of photocarcinogenesis (transformation of normal cells into cancer cells by UV radiation). In a randomized study, the intake of tomato paste, which is rich in lycopene, was shown to protect the skin against the effects of UV radiation such as redness and DNA damage.
The orange dye from carrots
Other studies have shown that intake of beta-carotene and lycopene, found in carrots and tomatoes, can protect against UV-mediated damage.
Studies in humans have produced conflicting results when studied specifically for skin cancer. For example, studies on the use of antioxidant supplements generally do not support the prevention of skin cancer.
Little scientific evidence for protection of antioxidant supplements against skin cancer
A randomized study found that the use of an antioxidant supplement consisting of vitamin C, vitamin E, beta-carotene, selenium and zinc did not affect the incidence of basal cell and squamous cell carcinoma (BCC and SCC).
In a 12-year study of more than 22,000 male physicians, 50 mg beta-carotene supplement did not affect the development of first basal cell and squamous cell carcinoma.
While you’re here
Estrogens in the blood affect a woman’s health in several ways. It contributes to stronger bones, faster wound healing and has an effect on skin aging. When menopause is reached, estrogen levels decrease and other hormones such as gonatropins (FSH and LH) increase.
Ultraviolet (UV) radiation can potentially negatively affect hormone levels in postmenopausal women and contribute to several health problems. More on sunbathing after menopause