Definition Neurodermatitis
Neurodermatitis is an eczema that occurs in infants as milk crust and in later life mainly affects the elbows, back of the knee and neck. Eczema is an acute or chronic disease of the epidermis (so-called epidermis) with extensive skin changes that are not clearly distinguishable from healthy skin. This is an inflammation.
The causes
The causes of neurodermatitis are not yet completely understood. There seem to be connections between the very complex course of the disease and the individual progressions with genetic factors, changes in the body’s own defense system and environmental influences. Also a psychosomatic component does not seem to be excluded as a cause for neurodermatitis.
Genetic factors seem to ensure that those affected react more strongly to certain influences than others. However, the exact scientific proof for this theory is still missing at present. The predisposition is inherited on several genes.
However, the onset and existence of the disease also depends on many external (exogenous) factors and internal (endogenous) modulation factors. Exogenous factors are for example food allergens, while endogenous factors include infections and psychological factors. A defect of the skin barrier is always at the beginning of the development of neurodermatitis.
Possibly, the cause is a local inflammation or a primary defect in the function of certain skin cells. This cell defect causes an increased release of messenger substances which attract inflammatory cells. A complex immunological process is set in motion, which corresponds to an allergic reaction.
Additionally, the barrier function of the skin is further disturbed, as the body’s own defense system causes further skin defects. Another theory of the cause of neurodermatitis suspects a kind of autoimmune disease, in which the body’s own defense system is directed against the own skin cells. Another cause could be a colonization of the skin and the mucous membrane by microogranisms.
It has been found that the skin and sinuses of people with neurodermatitis are often too heavily colonized by Staphylococcus aureus bacteria. These bacteria penetrate through the already existing skin defects into the skin and produce enterotoxins. Enterotoxins are toxic proteins against which the body’s own defense system forms antibodies.
In this way, the inflammatory reaction of neurodermatitis is further intensified. Similar strengthening reactions are conceivable with fungi such as Pityrosporum ovale or Candida albicans as well as with various viruses. Several disorders play a role in the disease of neurodermatitis.
Allergen contact leads to an inflammatory reaction in which immunoglobulins and messenger substances, so-called cytokines, play a major role. The itching is mainly triggered by the subsequent release of histamine from certain cells. Biochemical disturbances are, for example, the reduced secretion of sebum from the sebaceous glands of the skin.
This results in dry skin with reduced barrier function. This results in water loss, reduced skin protection mantle with easier penetration of foreign substances and increased itching. All these disorders have a certain genetic disposition, so we are given the tendency to neurodermatitis on our genes.
