[Therapeutic value of antihistamines today. Dermatoses and allergic diseases of the mucous membranes].

Factors to consider while administering antihistaminic agents: The dosage and time of administration should be related to the expected histamine release or the histamine release which has already taken place. The antihistaminic agents selected for treatment must take a) the type of receptor that is to be blocked (H1, H2), and b) additional pharmacologic properties such as sedation into account. H1-antagonists can be used to treat symptoms of various forms of acute and chronic urticaria, including physical urticaria, cholinergic urticaria and allergic rhinitis. Their indication for allergic forms of bronchial asthma has limitations. Antihistamines suppress the starter function of histamines and therefore, the development of further mediators. Furthermore, they influence the role of histamines in physiologic neurotransmitter processes. The combination of H1- and H2-antagonists can be beneficial in certain cases. Topical application of H1-antagonists leads to an anaesthetising , antipruritic effect and limits vessel permeability. The effect is noticeable after approximately 30 minutes. It is of therapeutical use if applied prior to histamine release.