Chronic autoimmune urticaria in children.

Results of determination of circulating histamine releasing autoantibodies using histamine release urticaria test in 12 children (aged 3 to 18 years, mean age 8.5 years; 7 female and 5 male) with chronic urticaria are presented. Standard work-up including detailed history, allergy testing and routine laboratory findings did not disclose any plausible cause of chronic/recurrent urticarial eruption in these children. All children underwent serum-induced basophil histamine release urticaria test. At serum dilution of 12.5%, the mean percent of histamine liberation was 40.8% (range 18%-77%; normal <16.5%), which indicated the presence of autoantibodies to Fc epsilon RI and/or to the IgE-Fc epsilon RI complex. The percent of histamine release did not correlate with patient age or duration and severity of symptoms. Thus the autoimmune basis of chronic urticaria was established. Associated antithyroid autoantibodies were found in two patients. Complete or partial remission was obtained with treatment that included antihistamines, low salicylate-low preservative diet in all, and high dose intravenous immunoglobulin in 3 children.