Neurodermatitis (atopic dermatitis)

There are various causes that are important in the development of neurodermatitis. To date, it has not been possible to precisely clarify their connections. It has been established that it is a hereditary disease. However, the illness itself is not inherited, but only the disposition to develop neurodermatitis or another atopic disease, such as hay fever or asthma. The risk here depends on the 'pre-history' of the family. If only one parent is affected, the risk for the child of having the disease is lower than if both parents are affected. Even without a pre-history in the family, every person has a certain risk of developing neurodermatitis.

What is inherited?

Neurodermatitis is a very complex, heterogeneous disease. Although it always results in very similar disease symptoms (dry skin, itching, an acute bout of skin inflammation, etc.), the disease can be traced individually to various causes. This depends, among others, on which genetic information is affected. It is now known that a mutation in the so-called filaggrin gene exists, in particular, with patients who already develop neurodermatitis at a very early age and have a tendency towards allergies. This results in a decisive disruption of the skin barrier function. Almost all neurodermatitis patients have an impaired skin protection barrier. In addition to a lack of filaggrin, this can also be caused by changed fat content in the uppermost skin layer, the epidermis, and by a lack of natural moisturising agents. Natural moisturising agents prevent water being lost via the skin through evaporation.
A damaged skin barrier facilitates the penetration of pathogens and allergens into the skin. One treatment goal is therefore to restore this impaired skin barrier and thus, the skin's natural protective function.

With some patients, changed genetic information in the area of the body's own defense, the immune system, play a role in the development of the disease. An overreaction of the immune system to normally harmless substances (allergy) can thus be observed on the one hand. On the other, the defence readiness for pathogens is reduced. Neurodermatitis patients therefore often have a tendency towards skin infections with bacteria, viruses, and fungi.

Main causes for the development of neurodermatitis are therefore a genetic disposition, an impaired skin barrier function, and a disrupted immune status.

However, external or triggering factors, so-called provocation factors also play a role in the development of the disease. The following examples should be mentioned:

• Infections caused by bacteria, viruses, or fungi
• Clothing when this can irritate the skin (e.g. wool, too tight clothing)
• Occupational irritant factors (e.g. chemicals at hairdressers)
• Climatic conditions (dry heating air, low humidity)
• Aero or food allergens (cow's milk, egg, hazelnuts, peanuts, soya, house dust mites, pollen, etc.)
• Furthermore, stress is 'poison' for neurodermatitis. Exam situations, marriage crises, divorce, death of a loved one, or conflict situations at the workplace can make the disease worse.

The coming together with numerous environmental factors, such as allergens or irritants, can therefore result in neurodermatitis breaking out or becoming worse.