[In which circumstances does the description of an etiology affect the treatment and the course of chronic urticaria?].

The causes of chronic urticaria are numerous but are not always authenticated, the idiopathic forms remainder majority. In the literature of these ten last years, the causes leading to a specific treatment remain very few. They are primarily thyroid disease or Helicobacter pylori infection. The association between chronic urticaria and thyroid autoimmunity seems to be shown. It concerns asymptomatic Hashimoto's thyroïditis and more rarely Basedow's disease. The analysis of the literature doesn't allow establishing the role of thyroid hormone on the urticaria course. Recent observations showed a high rate of prevalence of Helicobacter pylori infection among patients suffering of chronic urticaria but some publications not found a statistically significant relation between these two pathologies. The differences observed in the urticaria course after eradication of Helicobacter pylori can result from a great variability in the methods used and the geographical origin of these series. In childhood, the causes being able to lead to a specific treatment are represented by various infections. Literature review does not reveal any controlled study and does not make it possible to establish the responsibility for these infections in the development of chronic urticaria and in the effectiveness of adapted treatment.