APPLICATION OF A COMPREHENSIVE EARLY CHILDHOOD ALLERGY QUESTIONNAIRE (CECAQ) Investigating the association between foetal thymus size and childhood allergies

Abstract

Introduction: Childhood allergies affect up to 20% of young children worldwide, representing a significant public health issue. These allergies arise from complex interactions between genetic and environmental factors. Emerging evidence underscores the role of immune programming in utero, influenced by maternal conditions, with the thymus gland being crucial for T lymphocyte development and immune regulation. This study investigates the association between foetal thymus size and the development of childhood allergies.

Methods:A cross-sectional study employed the Comprehensive Early Childhood Allergy Questionnaire (CECAQ) to assess common childhood allergies (e.g., eczema, food allergies, asthma) in children aged 12 months to 5 years, surveying a total of 716 participants. Foetal thymus size was measured from ultrasound images (18–21 weeks gestation) at Nepean Hospital. Chi-square tests and multivariable analyses were performed using SAS software (v9.2). Ethical approval was obtained (Approval No. 12/58 - HREC/12/NEPEAN/119).

Results:Among 657 children with measurable thymus glands, 43.2% had at least one atopic Among 657 children with measurable thymus glands, 43.2% had at least one atopic condition (22.7% asthma, 23% eczema, 19.4% food allergies). No significant difference in thymus size was found between children with (M=22.63 mm, SD=3.03) and without atopy (M=22.79 mm, SD=3.08; P=0.484). Adjusted analyses found no significant associations with asthma or eczema; however, a smaller thymus size correlated with a 12% increased risk of food allergies and a 13% increased risk of severe food allergies.

Conclusion:This study is the first to explore foetal thymus size and childhood allergies. While no significant associations were found for asthma or eczema, a smaller thymus was linked to a higher risk of food allergies, particularly severe cases, underscoring the thymus's potential role in immune development and allergy risk.