Eczema in general

The causes of eczemas are diverse and to date have not been precisely clarified. In contrast to e.g. skin infections and fungi, viruses and bacteria (which incidentally frequently cause a similar clinical pattern to eczemas), the actual cause is often not clear.

A distinction is made between internal and external causes:

• Internal (endogenous) causes originate in the body itself. For instance, certain genetic information (genes) can result in a higher willingness of the immune system to react and thus result e.g. in a stronger or quicker inflammatory reaction of the skin. The topmost layer of skin can also have a genetic impairment so that the protection function of the skin is reduced and allergens and disease pathogens penetrate more quickly and come into contact with the immune cells located in the skin. A cycle of inflammation can thus be set in motion. Neurodermatitis is e. g. based on a genetic tendency to allergic diseases.
• External (exogenous) causes for eczemas are e.g. mechanical or chemical irritants or also substances that cause allergies. The climate can also affect the condition of the skin. For instance, more people suffer from a dry, tense and scaly skin in the winter with cold, dry air. This in turn can favour the development of eczemas.

Detailed information on the causes of the various eczemas can be found on the page of the respective form of eczema.

• Atopic eczema (= neurodermatitis)
• Acute or chronic contact eczema (allergic or irritating/toxic)
• Nummular eczema
• Seborrhoeic eczema