ACTINIC KERATOSES

Actinic keratoses (AK’s) or Solar Keratoses, consist of rough patches of skin mainly found on the face and exposed areas of the skin. They are very common in people who have had important sun exposure throughout their life, particularly in fair skinned people. AK’s don’t represent a real danger; however, if left alone, a few of them may turn into a particular kind of skin cancer named Squamous Cell Carcinoma (SCC).

Causes:

The major cause of AK’s is repeated sun exposure. Radiation from other sources can also produce them, for example sun beds. Bear in mind that the term “sun exposure” refers to not only sitting in the sun or sunbathing, but also to being outdoors as a result of any outdoor activity.

Sun damage in general and AK´s in particular are more frequent in fair skinned people who burn easily and seldom get tanned.

They are not contagious in any way as they are not infectious, and neither they are hereditary. However, a fair complexion may be inherited and, therefore, some families may be more prone to suffering from them.

Symptoms

Normally they are perceived as dry or reddish patches of skin that often become crusted and rough to the touch. The crust may fall off only to re-appear in the next following days or weeks. They may be slightly tender and/or sore. Sometimes they get inflamed and angry-looking for no apparent reason. Some of them grow quickly and may produce a cutaneous horn, which is firmly attached to the skin.

They may also be brownish, yellowish or greyish in colour and if they grow quickly, become painful, bleed, etc. you should seek for advice to ensure that they have not turned into a skin cancer.

The commonly affected areas are the face, the scalp in bold people, the top of the ears, the back of the hands and forearms, the back and the chest. It is also common to find them on the legs, particularly in ladies.

Diagnosis

A Dermatologist is normally able to diagnose them straight away (by their appearance and texture), but in any doubt a small biopsy may be performed to confirm the diagnosis.

Treatment

It is unlikely that these lesions resolve on their own but fortunately they are easy to treat. The aim of the treatment is not only to improve the cosmetic appearance but also to reduce the possibilities of them turning into a malignant condition.

Some of the lesions may recur after treatment, and some others may also develop in the surrounding sun-damaged skin.

AK’s can be left alone if they are not causing any problems but they need reviewing on a regular basis to exclude malignant transformation. There are different treatments available:

• Liquid Nitrogen. It is a very cold liquid that freezes the skin instantly after sprayed onto it. This produces a burnt by freezing. The therapy is slightly painful and stingy when applied, and normally it leaves a sore area that may transform into a blister. Some days later a crust will be appear and a new healthy skin will replace the damaged one. The procedure may rarely produce some white or dark marks on the treated area.
• Creams. Different substances (5-Fluoracil, imiquimod) target the damaged cells and destroy them by causing inflammation. This process is necessary for the resolution of the lesions and it may be uncomfortable, as the treatment requires to be continued for few weeks. Other creams may help to avoid new lesions from coming up (retinol derivatives).
• Surgical removal under local anaesthetic. They can be completely cut out or curetted (scraped off from the surface). This may be a good approach if the number of lesions is reduced.
• Other treatments: An example is the Photodynamic Therapy (a sensitizing cream is applied onto the skin and the area is then exposed to a special source of light, which produces a burnt). This is an effective treatment, but is not widely used.

All these treatment may need to be repeated several times over the course of years.

Prevention

It is very important to keep away from the sun as much as possible. Try and avoid staying out in the sun for long time in the central hours of the day. Physical measures such as the use of long sleeves, hats etc, are very helpful. Sunscreens must also be used and they should have a sun protection factor above 30. Make sure they protect against Ultraviolet B (UVB) and Ultraviolet A (UVA) radiation. The sunscreen has to be applied half an hour before any sun exposure, and its application has to be repeated every 2 to 3 hours. Remember that even on a cloudy day you may get burnt if not adequately protected.

Should you have any further questions, do not hesitate to contact your Dermatologist.