The aim of this study was to investigate the role of autoimmunity in children and adolescents with chronic urticaria.

We have studied 38 children aged 2 to 17 years-old (20 females), who were referred to the allergy clinic for evaluation of chronic urticaria in the preceding 4 years. Age at onset of symptoms varied from 6 months to 15 years (mean 5.3 years), duration of symptoms ranged from 6 weeks to 10 years (mean 2.4 years), and 63% patients also presented angioedema. Each patient underwent clinical evaluation, skin prick testing with inhalant and food allergens, and blood testing including detection of anti-nuclear antibodies, antithyroid antibodies, thyroxine and TSH levels and measurements of total IgE and specific IgE antibodies (Pharmacia CAP system). Autologous skin testing was carried out in 28/38 patients.

Positive skin tests and/or serum IgE antibodies (CAP score ≥2) to inhalant and food allergens were detected in 65% and 76% of patients, respectively. Associated conditions were (number of patients): allergic rhinitis (14), asthma (5), precocious puberty (2), atopic dermatitis, JRA and anaphylaxis to insect sting (1 each). Evidence for autoimmunity was present in a subset of children: 15/28 (53%) had a positive autologous skin test and 3/30 had positive ANA (≥1:20). Two patients had elevated TSH (>4 mIU/L) with normal thyroxine levels, and no patient had detectable (≥35 IU/mL) antithyroid peroxidase antibodies.

An autoimmune mechanism may underlie the pathogenesis of chronic urticaria in a subset of children with this condition.