Actinic Keratoses (Cornification Disorders)
Actinic keratoses are the result of genetic changes in skin cells caused by sun exposure. They are considered to be the early stage of white skin cancer (squamous cell carcinoma). Most often they occur in sun-exposed areas of the body, i.e. on the head (formerly hairy scalp) in the decollete, on the face (often on the nose or forehead), on the backs of the hands or arms.
They express themselves as punctiform areas with a rough surface and are therefore more palpable than visible. In addition to the change similar to sandpaper, there is usually a reddening.
The medical history asks whether the person concerned has often been exposed to unprotected sun rays in the past. The clinical picture together with the palpation of the roughness gives sufficient information about the present situation. Dermoscopic or reflected light microscopic imaging with a subsequent histological cell examination after a sample is taken confirms the suspected diagnosis.
Drug therapy with certain active ingredients, e.g. Fluorouracil as a cell poison can be applied selectively to actinic keratoses in the form of creams or ointments. These ignite easily and new skin formation is stimulated. This can be done in a mild form over several weeks or in a strong form with more violent reactions in three days. In addition, selective cryotherapy with -180 ° C cold nitrogen is an alternative. If there is a field cancerization, i.e. a large-scale infestation, photodynamic therapy is recommended.
The skin is opened slightly with a fractionated laser and a cream with the active ingredient methylaminolevunilate is applied. This is followed by a two-hour stay outdoors. This does not have to mean that the treated areas have to be exposed to the sun. A minimum lux number ensures that the active ingredient reacts on the skin. After the two hours, the skin is treated in the practice. In the following three days, strong reactions develop in the form of redness and crust formation, which can last up to two weeks. The more pronounced the cancerization, the more pronounced this is in the subsequent skin reaction. Despite the unusual appearance, this is a desired side effect, since the formation of new skin causes the actinic keratoses to disappear. A medical check-up also takes place after three days. Normally, all new skin changes recede and leave a freshly formed, smooth, healthy skin.