Background: Oxidative stress may play a role in the pathophysiology of several diseases including allergic rhinitis.

Objectives: To evaluate whether plasma total oxidant status (TOS) in the form of plasma reactive oxidants differs between children with allergic rhinitis and healthy controls and to investigate associations between plasma antioxidants and other allergic rhinitis–related immunological markers.

Materials and Methods: Plasma total antioxidant status (TAS), TOS, total eosinophil count, and total serum immunoglobulin (Ig) E levels were measured in 106 children newly diagnosed with allergic rhinitis and 70 nonallergic children (7-12 years of age). Plasma TAS and TOS were measured using novel automated measurement methods. Blood eosinophils (absolute counts and percentage of total white blood cells) and total IgE were elevated in children with allergic rhinitis after adjusting for age and sex.

Results: TAS and TOS were higher in the patient group than in the control group (P<.001 and P<.002, respectively). The association between plasma TAS and TOS and allergic rhinitis status was similar when eosinophils, total IgE, and allergic sensitization were included as possible confounders in logistic regression models. Multivariate logistic regression identified allergic rhinitis as the only independent factor contributing to TOS.

Conclusion: Plasma TAS and TOS levels are elevated in children with allergic rhinitis. Moreover, the high level of TOS indicates that these patients are exposed to severe oxidative stress. This stress factor may have a role in the pathogenesis of allergic rhinitis.

Key words: Total oxidant stress. Allergic rhinitis. Children.