Age and Seasonal Variation in Allergen Sensitivity Among Children: A Comprehensive Analysis of Food and Environmental Allergens

Background Allergic conditions, particularly food and environmental allergies, are increasingly recognized as important contributors to pediatric morbidity worldwide. However, data describing age-related and seasonal patterns of allergen sensitization in children from low- and middle-income countries remain limited. This retrospective, cross-sectional, laboratory-based study aimed to evaluate the frequency and seasonal variation of food and environmental allergen sensitization among children undergoing allergen-specific IgE testing. Methods A total of 2,796 pediatric patients (1,676 males and 1,120 females) under 18 years of age who underwent allergen-specific IgE testing between January 2013 and July 2023 were included. Participants were categorized into four age groups: <1, 2-5, 6-10, and 11-18 years. Six food allergens and eight environmental allergens were analyzed using the IMMULITE® 2000 system (Siemens Healthcare Diagnostics Inc., Deerfield, IL, USA) with 3gAllergy® kits. Specific IgE ≥0.35 kU/L was considered positive. Associations between allergen positivity, age, sex, and season were assessed using chi-square and Kruskal-Wallis tests. Results Dermatophagoides farinae (52.5%) and Dermatophagoides pteronyssinus (52.1%) were the most frequently detected environmental allergens, while egg white (30%) and shrimp (28.7%) were the most common food allergens. Environmental allergen positivity was higher in younger children, whereas food allergen positivity peaked in adolescents (11-18 years). Male participants demonstrated higher overall allergen positivity rates. Significant seasonal variation was observed, with increased sensitization during autumn and winter months. Conclusions This study characterizes patterns of allergen sensitization within a clinically tested pediatric cohort in Pakistan, demonstrating age- and season-related variation in allergen-specific IgE positivity. As a laboratory-based analysis, the findings reflect immunologic sensitization rather than confirmed clinical allergy and should not be interpreted as population-level prevalence. These data provide region-specific insights that may support clinical evaluation and patient counseling in similar settings.