Egg allergy in infancy predicts respiratory allergic disease by 4 years of age

Area of Science:

• Pediatric Allergy and Immunology
• Environmental Health
• Epidemiology

Background:

• Early-life sensitization to hen's egg is a known predictor of childhood respiratory allergies.
• The role of symptomatic egg allergy in infancy as a predictor for subsequent respiratory allergic diseases has not been extensively studied.

Purpose of the Study:

• To investigate the association between symptomatic egg allergy in infancy and the development of respiratory allergic diseases at four years of age.
• To determine the predictive value of infant egg allergy, with and without coexisting infantile eczema or family history of atopy, for respiratory allergic disease and aero-allergen sensitization.

Main Methods:

• A birth cohort of 1,218 children was recruited in 1989, with data on family history and environmental factors collected.
• At four years of age, 981 children underwent skin-prick testing for food and aero-allergens.
• Statistical analyses, including odds ratios and positive predictive values, were used to assess associations.

Main Results:

• Infant egg allergy was significantly associated with increased respiratory allergic disease (asthma, rhinitis) at age four (OR 5.0, PPV 55.0%).
• The addition of infantile eczema to infant egg allergy increased the positive predictive value to 80%.
• Infant egg allergy also increased aero-allergen sensitization (OR 6.1, PPV 61.1%) and demonstrated high specificity but poor sensitivity as a predictor.

Conclusions:

• Symptomatic egg allergy in infancy is a significant predictor of respiratory allergic disease and aero-allergen sensitization in early childhood.
• The presence of infantile eczema alongside egg allergy substantially enhances its predictive value for respiratory allergies.
• While egg allergy in infancy shows high specificity, its poor sensitivity suggests it is not a universal predictor for all children who develop respiratory allergies.