[Treatment of chronic idiopathic urticaria unresponsive to type 1 antihistamines in monotherapy]

The chronic idiopathic urticaria treatment is a difficult and often frustrating problem for physicians. Due to the lack of definitive medical therapeutic programs to relieve the symptoms and prevent from their recurrence, several pharmacologic approaches to the management of chronic idiopathic urticaria are proposed. The chronic urticaria pharmacologic therapy is therefore fit to abrogate effects of histamine and other mediators on cutaneous vasculature and inflammatory cells that participate in the pathogenesis of the urticaria. The most common approach is to avoid all aggravating factors and to block histamine. The mainstay therapy is the H1 antihistamines. A significant number of patients may remain unresponsive even after an increase in the dose or a change in the type of H1 antihistaminic drug. In these cases, several therapies can be associated: combinations of H1 antihistamines, nonsedating one tablet (morning) and one sedating (evening), this approach is very usual but no study has confirmed it rational; addition an H2 antagonist to the previous treatment for some patients may improve control of their symptoms; alternatively, the tricyclic antidepressant, Doxepin is usually prescribed. The results of other drugs reported in the literature is unpredictable, to include them in a strategy therapy. The results with Badrenergic agents, nifedipine, ketotifen, leukotriene antagonists and tranexamic acid are variable and don't appear better than those with H1 antagonists. The efficiency of danazol has to be confirmed by other controlled studies. Warfarin, sulfasalazine and ultraviolet radiation have been used apparently successfully, but no controlled study has been published. Only when the above treatments have failed then immunosuppresive therapies, intravenous immunoglobulin and plasmapheresis can be proposed for chronic idiopathic urticaria.