Keratoses are cornification disorders of the skin with horny and scaly deposits.
Typical diseases associated with keratoses include actinic keratosis (noninvasive, early (in situ) squamous cell carcinoma), seborrheic keratosis (senile wart), and keratosis actinica (light keratosis).
Pathogenesis (disease development) – etiology (causes)
In general, a skin cell requires approximately 28 days from maturation to death. Dead skin cells are shed by human movement or friction against clothing. In the case of cornification disorder, this process is disturbed. The life span of the skin cells is shortened or the dead skin cells are not removed – thick horny skin layers are formed.
The causes of cornification disorders are manifold. On the one hand, they are genetically determined – ichthyosis (scaly changed skin), palmoplantar keratosis (cornification of palms and soles) – on the other hand, they are acquired – hyperkeratosis (excessive thickening of horny layer ) after arsenic, tar exposure, occupational keratosis, radiation exposure, sun rays (photoaging), vitamin A deficiency.
Hyperkeratosis is characterized by thickening of the horny layer (stratum corneum) of the epidermis. One speaks of parakeratosis when irregular cell nuclei are seen in the stratum corneum. The term dyskeratosis is used for disturbed keratinization.
Prophylaxis
- Protection from UV rays (photoprotective measures).
Therapy
- Establishing the diagnosis of the type of keratinization disorder (biopsy (tissue sampling) and histologic (fine tissue) examination, if necessary).
- Cornification should be creamed daily and removed regularly.
- If necessary, a peeling (eg fruit acid peeling) can be performed every 14 days.
- In the case of very advanced cornification, a surgical procedure may be necessary.
- By means of erbium Yag laser is also possible to remove the cornifications.