Comparison of allergen types and complete blood count in pediatric allergic rhinitis

Allergic rhinitis (AR) is a highly prevalent immunoglobulin E (IgE)-mediated disease that significantly impacts quality of life. While hematological parameters (complete blood count [CBC]) are linked to inflammation in adult AR, their relevance to pediatric populations remains unclear. This study aimed to characterize allergen sensitization profiles, CBC parameters, and immunoglobulin features in pediatric AR patients across demographic subgroups (sex, age, disease duration).

A retrospective study included 253 children with AR (aged 3-12 years; 176 males, 77 females) who tested positive for specific IgE (sIgE) to one or more inhalant allergens (≥ 0.35 IU/mL). Demographics, symptom scores (nasal/ocular), family history, sIgE, CBC, total immunoglobulin E (tIgE), immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), and complement component 4 (C4) were assessed. Statistical analyses were performed to compare groups based on sex, age (preschool vs. school-age), and disease duration, and to examine correlations between parameters and symptom scores.

House dust mites (HDM) (including Dermatophagoides farinae [D. farinae]: 98.81% and Dermatophagoides pteronyssinus [D. pteronyssinus]: 97.63%) were the predominant sensitizing allergens, predominantly with high-grade sensitization (classes 3-6). Males exhibited significantly higher tIgE, D. farinae sIgE, D. pteronyssinus sIgE, German cockroach sIgE, IgA, C4, neutrophils, monocytes, red blood cell (RBC) count, red cell distribution width-coefficient of variation (RDW-CV), and mean corpuscular volume (MCV) compared to females. School-age children and those with longer disease duration had higher HDM sensitization rates (classes 3-6), Total Nasal Symptom Score (TNSS), IgG, IgA, neutrophils, and specific platelet indices (mean platelet volume [MPV], platelet-large cell ratio [P-LCR]), but lower eosinophils compared to preschoolers or those with short disease duration. Eosinophils, basophils, neutrophils, platelets, tIgE, HDM-sIgE, IgA, hematocrit (HCT), and red cell distribution width-standard deviation (RDW-SD) correlated significantly with nasal symptom scores. After adjusting for multiple comparisons and confounding factors, IgA remained independently associated with longer disease duration and showed significant correlations with nasal symptom scores.

HDM are the primary allergens in the pediatric AR population in Guangzhou. Significant sex-, age-, and duration-related differences exist in sensitization patterns and immune and CBC profiles. After rigorous statistical control for multiple comparisons, only total IgE, absolute basophil count, and eosinophil percentage correlated significantly with symptom severity, highlighting their potential as accessible biomarkers for assessing disease activity.