Actinic keratosis

An early form of this type of skin cancer is actinic keratosis. The disease is limited to the epidermis and is associated with increased keratinization; the skin areas are rough and slightly thickened as a result. If the actinic keratosis grows into the dermis, a prickle cell carcinoma develops. Actinic keratosis is caused by intense sun exposure over long periods of time. If actinic keratosis is treated early, it has a good chance of being cured. It mainly affects fair skin types and usually develops in people over 50, but younger people are also increasingly suffering from this sun-related skin change.

What is actinic keratosis?

Actinic keratosis is caused by too much UV radiation, be it natural sunlight or artificial UV rays in a solarium. The damage to the skin accumulates over the years – there is something like a lifetime dose of UV rays. This is one of the reasons why older people are the first to develop actinic keratosis. The damaged skin reacts by forming light-colored or reddish patches that flake slightly whitish. Over time, these areas become keratinized and harden and slowly spread from small spots to larger and larger areas. Areas of skin that are anatomically exposed and usually unprotected from the sun are predestined for actinic keratosis:

• Forehead and bald head
• Bridge of the nose, skin on the cheekbones
• auricles, lips
• Back of the hand
• Décolleté and scalp
• Forearms, shins, calves

Normally, the top layer of skin (epidermis) regenerates very well after intensive sun exposure or sunburn. However, if there is too much direct sunlight over long periods of time, the skin cells take offense. In the first phase, the UV light damages the cells of the epidermis. The damage (lesions) is not visible at first. The nuclei of the skin cells change. The corneal cells begin to multiply in a disorganized manner and the corneal layer thickens. The damage looks like skin growths and feels rough and coarse. The skin lesions usually grow in several places and spread over a large area in small groups. As a layperson, it is not so easy to recognize and identify the skin damage, but you can feel the difference on the surface of the skin: the altered areas are rough and coarse and sometimes a little raised.

Initially, the altered (malignant) cells remain confined to the uppermost layer of the skin. At this stage, actinic keratosis is easily treatable. At some point, the altered cells then begin to penetrate into deeper tissue layers. A spinalioma develops, the actinic keratosis has developed into a prickle cell carcinoma. Even at this stage, the earlier the treatment takes place, the better.

Actinic keratosis: causes and risk factors

Anyone who exposes themselves to the sun without protection for long periods of time runs the risk of developing actinic keratosis. If areas of skin have to repeatedly endure extreme sun exposure, the overstressed skin cells suffer. They no longer regenerate, accumulate the damage, so to speak, and begin to change genetically. The epidermal keratinocytes, the corneal cells, continue to grow irregularly and uncontrollably. Actinic keratosis can develop into white skin cancer, which is why corneal accumulations are also seen as a possible risky precursor. As a rule, older people are more at risk of developing actinic keratosis due to their accumulated “sun experience”. Experts therefore also speak of senile keratosis. However, excessive unprotected sunbathing or too frequent visits to the solarium are increasingly causing younger people to develop this possible precancerous condition.

The particular risk factors for actinic keratosis include

• UV-sensitive skin type
• Frequent leisure activities in the sun
• Occupations with a lot of sun exposure
• Severe sunburns in childhood
• Impaired immune system due to illness or drug treatment

Actinic keratosis can appear and disappear again for a certain period of time. However, this disease does not heal on its own.

Symptoms: Actinic keratosis

Actinic keratosis appears on the areas most exposed to the sun, the so-called sun terraces. It can manifest itself with different skin changes and is therefore not always clearly recognizable. If you spend a lot of time in the sun, you should check your skin regularly. Small red spots are an early sign. The top layer of skin has become thinner here due to the intense sunlight and the blood vessels become more prominent. Over time, these areas develop into small keratinized patches that feel rough and uneven. White scaly crusts are another sign that it could be actinic keratosis. The skin changes can also be associated with a feeling of tightness, minor bleeding, itching or pain.

Seek medical advice or go to hospital if you notice the following:

• red scaly patches on the back of the hand
• Reddish incrustations on the cheek or the auricles
• Rough patches of skin on the forehead or bald head
• encrusted cracks on the lower lip

Skin changes on the forearms, shins or calves should also be taken seriously. It makes no sense to pluck off the keratinized scaly patches and treat the affected skin areas with an oily cream. The damage has already been done, the aids have at most a temporary visual effect. Seeing a dermatologist is the right thing to do, as it is possible to intervene effectively and successfully at an early stage.

Diagnosis of actinic keratosis

If the doctor suspects that you have actinic keratosis or prickle cell carcinoma, a tissue sample will be taken and examined under a microscope. If the suspicion is confirmed, the skin cancer or its precursor must be completely removed. Various treatment options are available, depending on the type, size, depth and location of the skin change, as well as the age and health of the patient. Outpatient treatment is almost always possible.

Actinic keratosis: prevention

The best protection against actinic keratosis is the sensible and controlled use of natural and artificial UV light. It doesn’t matter whether you spend a lot of time in the sun in your free time or for professional reasons. An Australian study also found that taking vitamin B3 (nicotinic acid / niacin) can reduce the incidence of actinic keratoses.

Other preventive measures may include

• Use high-quality sunscreen
• protect the skin on your arms with thin clothing
• protect your head with a sun hat or cap
• Protect children from the sun with caps and cream
• prefer to stay in the shade
• Avoid blazing midday sun

People who work predominantly outdoors are at particular risk and must also be properly protected by their employer. Remember that there is UV radiation even when the sky is overcast. Keep a close eye on your skin, especially in summer, and it’s better to have one check-up too many than too few. Compared to other European countries, the skin cancer rate in Switzerland is very high. You should therefore take advantage of preventive examinations for the early detection of skin cancer.

Actinic keratosis – course and prognosis

If actinic keratosis is detected and treated at an early stage, it can take a favorable course. After successful treatment, however, regular skin checks remain important. It is also important that you control your “sun consumption”, only go out in the sun with protection, avoid direct sunlight and look after your skin carefully. This is because it does not forget the damage it has experienced. However, as actinic keratosis lasts a lifetime, you must continue to protect yourself well from UV rays even after successful treatment.

Actinic keratosis - treatment

Actinic keratoses can usually be removed largely without scarring using a whole range of treatment methods.