Blood eosinophil counts as a biomarker for allergen sensitization in childhood allergic diseases in comparison with total IgE

Purpose: Eosinophils and total immunoglobulin (IgE) have served as a histologic hallmark of allergic conditions. Many investigators have used total eosinophil count (TEC) and total IgE for evaluating allergic diseases. We examined differences in TEC and total IgE in allergic diseases and whether it differs according to sensitization. Methods: In this retrospective study, we enrolled 551 patients who visited Uijeongbu St. Mary’s Hospital from January 1, 2009 through December 31, 2012 for allergic diseases. We included patients with a diagnosis of atopic dermatitis (AD), allergic rhinitis (AR), asthma (AS), or urticaria (UC). We compared the TEC and total IgE level according to sensitization patterns. Results: There were 235 cases of AD, 179 cases of AS, 112 cases of AR, and 82 cases of UC. Regarding sensitization, 106 were not sensitized to any allergens, 206 were sensitized to inhalants, 109 were sensitized to food allergens, and 49 were sensitized to both food and inhalant allergens. TEC was significantly higher in the AD and AR group than in the UC group. TEC was significantly higher in those sensitized to both inhalant and food than those not sensitized. The total IgE levels were significantly higher in those sensitized to both inhalant and food than those not sensitized or sensitized to food. Total IgE levels were significantly higher in those sensitized to inhalant than those not sensitized or sensitized to food. Conclusion: Eosinophils appear to play differential roles in the expression of different types of allergic diseases. Total IgE level may play a significant role in sensitization. (Allergy Asthma Respir Dis 2024;12:26-30)