[Intolerance reactions of the skin].

Intolerance reactions of the skin in which a decision is made on allergic and toxic genesis have increased in significance in recent years. Whereas antibodies blocking bacterial or viral antigens are formed in the normergic immune reaction, nonblocking antibodies to animal, plant or chemical heterologous substances are formed in an allergy as a result of an misdirected immunological reaction. Sensitization is favored by a) large structure and protein affinity of the allergen, b) irritation of the affected part of the skin by fungi or chemicals and c) genetic predisposition. Depending on the clinical manifestation, a distinction is made between inhaled allergens (bronchial asthma, hay fever), allergens ingested with the food (food allergy) and allergens which have come in contact with the skin (immediate reaction - urticaria, late reaction - contact eczema). Intolerance reactions of the skin which can be ruled out as the cause of an allergy are designated as toxic. Acute toxic reactions are based on violent or intensively physical (heat, cold, radiation), chemical (acids, alkalis, heavy metal salts, oils, solvents) or microbial damage to the skin (infection by fungi, bacteria, viruses). The degenerative eczema as the most important form of chronic toxic intolerance reaction arises by weak but continuously acting longterm mechanical or chemical exposures.