Proceedings of the Canadian society of allergy and clinical immunology annual scientific meeting 2015

Elinor Simons1, Allan B. Becker1, Rishma Chooniedass1, Kyla Hildebrand2, Edmond S. Chan2, Stuart Turvey2, Padmaja Subbarao3, Malcolm Sears4 1Section of Allergy and Immunology, Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada, 2Division of Allergy and Immunology, Department of Pediatrics, British Columbia Children’s Hospital, Vancouver, BC, Canada, 3Department of Pediatrics, Hospital for Sick Children, Toronto, ON, Canada, 4Division of Respirology, Department of Medicine, McMaster University, Hamilton, ON, Canada Correspondence: Elinor Simons - elinor.simons@umanitoba.ca Allergy, Asthma and Clinical Immunology 2016, 12(Suppl 1):A60 Background: Sensitization to peanut places a child at risk for anaphylaxis to peanut, although some peanut-sensitized children tolerate eating peanut. We evaluated the association between timing of peanut introduction in infancy and development of reactions and sensitization to peanut by age 3 years. Methods: Caregivers of participants in the population-based Canadian Healthy Infant Longitudinal Development (CHILD) Study prospectively reported their child’s first introduction and reactions to peanut starting at age 6 months. At ages 1 and 3 years, the children underwent skin prick testing for sensitization to peanut and other food allergens, and an assessment for eczema/atopic dermatitis. We conducted multivariable logistic regression to determine if later introduction of peanut was associated with increased odds of reactions and sensitization to peanut. Results: Among participants from the Manitoba and Vancouver sites (n = 1610), peanut was introduced into the diet at ages 6 (1.3 %), 9 (14.1 %), 12 (27.4 %) and >12 (42.3 %) months; 14.9 % had not tried peanut by 18 months. At age 1 year, 2.4 % of children had moderate-to-severe eczema. By age 3 years, 5.6 % of children had a reaction to peanut and 7.2 % had at least one positive skin prick test to peanut, 3.4 % to milk, and 9.3 % to egg. In the first 3 years, 53.9 % of peanut-sensitized children had reacted to peanut and 77.8 % of children who had reacted to peanut were peanut-sensitized. Children with later peanut introduction (on a continuous scale from 6–18 months) had higher odds of a reaction (1.04; 95 % CI 1.02–1.06) and sensitization (1.04; 1.03–1.05) to peanut, after adjustment for sensitization to egg and moderate-to-severe eczema. Conclusion: In a population-based sample of Canadian children, later peanut introduction was associated with reported reactions and sensitization to peanut by age 3 years. Further investigation is needed to characterize the association between timing of peanut introduction and persistent peanut allergy.