Chronic urticaria and coeliac disease.

We appreciated the paper by Levy et al published in this journal in June 2003. A number of the cases of chronic urticaria in children appear to be of unknown aetiology, and experiences such as the one reported by the authors indicate an autoimmune origin. In our opinion the model of association between thyroiditis and chronic urticaria may apply to the association between coeliac disease and chronic urticaria as well. Remarkably, Levy et al described a coeliac child with both chronic urticaria and autoimmune thyroiditis. In the literature, reports of at least four other cases of association between chronic urticaria and coeliac disease that improved after a gluten-free diet have been found, together with a report of a case of a coeliac 11 year old girl with chronic urticaria unresponsive to the diet. Our experience confirms that chronic urticaria may be associated with coeliac disease. We tested 32 children and adolescents with idiopathic chronic urticaria for tissue transglutaminase antibodies. HLA typing was performed in 25 of these patients; 10 tested positive for the typical coeliac aplotype DQ2DQ8. Three of 10 tested positive for tTG. None of the HLA negative children tested positive for tTG. In these three children a small bowel biopsy confirmed coeliac disease, and all showed an improvement or a resolution of the urticaria with a gluten-free diet. Some evidence suggests that the duration of exposure to gluten in coeliac subjects is related to the risk of developing other autoimmune diseases. The hypothesis is that in coeliac disease the decrease of the immunological stimulus with the diet may decrease the production of other autoantibodies. This could possibly explain the improvements described after the adoption of a gluten-free diet in subjects with subclinical coeliac disease associated with chronic urticaria. Therefore, even if this association is rare, we think that it is important to extend the field of investigation in the area of autoimmunity, screening for coeliac disease all subjects affected by chronic urticaria of unknown origin. This recommendation is strengthened by the consideration that the diet for coeliac disease could help their urticaria to improve, and may prevent the development of other types of autoimmune disorders.