Context • Allergic rhinitis is a chronic disease that usually affects children. Its etiology has been investigated for years.
Objective • The aim of the study was to evaluate the diagnostic value of immunoglobulin G4 (IgG4) against common food allergens, to determine the correlation between it and immunoglobulin E (IgE), and to evaluate the role of IgG4 (ie, whether its presence should be considered to be a significant factor that induces hypersensitivity or whether an effector role in allergic rhinitis could be attributed to it).
Design • This research was conducted as a randomized controlled trial.
Setting • The research team performed the study in the Department of Otolaryngology and Sleep Center, Cheng Ching General Hospital-Chung Kang Branch (Taichung, Taiwan).
Participants • The participants were 46 patients—29 boys and 17 girls—with an average age of 8.02 ± 2.92 y—who had been diagnosed with allergic rhinitis.
Outcome Measures • Blood samples were collected from the participants. The total IgE, food-specific IgE, and food-specific IgG4 in their sera were measured using the proprietary BioIC system, which is based on the principles of the enzyme-linked immunosorbent assay (ELISA).
Results • In terms of total IgE, 20 patients (43.5%) had a concentration of <100 IU/mL, and 7 patients (15.2%) had levels between 100 and 199 IU/ml; 6 participants (13.0%) had levels between 200 and 299 IU/mL, 3 participants (6.5%) had levels between 300 and 399 IU/mL,
2 participants (4.3%) had levels between 400 and 499 IU/mL, 4 participants (8.7%) had a concentration from 500 to 1000 IU/mL, and 4 participants (8.7%) had a concentration of >1000 IU/mL. Regarding specific IgG4, 89.1% of patients were highly reactive to egg white IgG4, whereas >50% were highly reactive to egg yolk, milk, peanuts, almonds, wheat, and soybeans. Regression analysis to test the correlation between specific IgE and specific IgG4 revealed that egg whites, milk, peanuts, and almonds had significant correlations (P < .05). Cod, shrimp, and crab showed very significant correlations (P < .001).
Conclusion • Total IgE varies widely in children with allergic rhinitis but remains one of the references for diagnosis. The main inhalational allergens are dust mites, followed by grass pollen, molds, German cockroach, and animal dander. Food allergy generates highly concentrated IgG4 and may play a role in children with allergic rhinitis.