Major progress has been achieved in our understanding of the pathophysiology of different forms of chronic urticaria during the last years. Most important is the understanding of chronic urticaria as a symptom than as a disease. This symptom is the result of a malfunction of basophiles and/or mast cells resulting in an increased release of histamine and other inflammatory mediators by these cells. The causes are quite different and include the release of these agents by toxic events induced by specific drugs or other substances known to be histamine releasers, allergic reactions which are in most cases IgE-mediated and autoimmune reactions. This progress resulted also in new therapeutic options such as cyclosporin A, intravenous immunoglobulin, plasmaphereses, chloroquine, sulfones, calcium antagonists, although antihistamines are still the first-line drugs in by far most cases of chronic urticaria. Therefore, the development of new antihistamines with less side effects, such as the antihistamines of the "second generation" or the latest development leading to fexofenadin, descarboxyloratadine and levoceterezine, compounds which establish a third generation of antihistamines in the treatment of urticaria.