[Treatment of chronic urticaria resistant to H1 antihistamines]

Urticaria is a syndrome. Several signalisation factors (cytokines and chemokines) are implicated in activation of mast cells receptors. Immunologic or non immunologic mechanisms elicit mediator releases and inflammatory activities inducing urticaria lesions. In chronic urticaria the removal of an hypothetical cause is not possible, and the therapeutic management is first oriented towards palliation of symptoms. H1 antagonists are the treatment of choice. Higher dosage than those recommended may be necessary. But severely affected patients are not enough improved. Triggering factors should be avoided. Addition of other mediator antagonists such as leukotriene receptor antagonists have improved some patients and need further evaluation. Several alternative pathogenic therapies have been proposed with conflicting results. Tolerance induction may be tried in a few cases of severe physical urticaria. Oral steroids are reserved if possible for systemic urticaria and in short course for severe exacerbation. Immunosuppressive agents are only appropriate for patients with refractory urticaria to classical treatment. Oral cyclosporine has been used with encouraging results. Its has a suspensive effect but relapses can be treated by H1 antagonists. Whichever the drug or association of drug individual variations in the course of the disease need periodic reevaluation. A spontaneous unexplained remission is not an exception. In this heterogeneous disease an individual approach is required, leading to reduction of symptoms with the least invasive therapy, carefully balancing risk and benefits.