title: The natural history and clinical predictors of egg allergy in the first 2 years of life: a prospective, population-based cohort study.
abstract: BACKGROUND
  There is a paucity of data examining the natural history of and risk factors for egg allergy persistence, the most common IgE-mediated food allergy in infants.
  
  
  OBJECTIVE
  We aimed to assess the natural history of egg allergy and identify clinical predictors for persistent egg allergy in a population-based cohort.
  
  
  METHODS
  The HealthNuts study is a prospective, population-based cohort study of 5276 infants who underwent skin prick tests to 4 allergens, including egg. Infants with a detectable wheal were offered hospital-based oral food challenges (OFCs) to egg, irrespective of skin prick test wheal sizes. Infants with challenge-confirmed raw egg allergy were offered baked egg OFCs at age 1 year and follow-up at age 2 years, with repeat OFCs to raw egg.
  
  
  RESULTS
  One hundred forty infants with challenge-confirmed egg allergy at age 1 year participated in the follow-up. Egg allergy resolved in 66 (47%) infants (95% CI, 37% to 56%) by 2 years of age; however, resolution was lower in children with baked egg allergy at age 1 year compared with baked egg tolerance (13% and 56%, respectively; adjusted odds ratio, 5.27; 95% CI, 1.36-20.50; P = .02). In the subgroup of infants who were tolerant to baked egg at age 1 year, frequent ingestion of baked egg (≥5 times per month) compared with infrequent ingestion (0-4 times per month) increased the likelihood of tolerance (adjusted odds ratio, 3.52; 95% CI, 1.38-8.98; P = .009). Mutation in the filaggrin gene was not associated with the resolution of either egg allergy or egg sensitization at age 2 years.
  
  
  CONCLUSIONS
  Phenotyping of egg allergy (baked egg tolerant vs allergic) should be considered in the management of this allergy because it has prognostic implications and eases dietary restrictions. Randomized controlled trials for egg oral immunotherapy should consider stratifying at baseline by the baked egg subphenotype to account for the differential rate of tolerance development.
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Peters
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Parkville, Australia.
authors.forename: Shyamali C
authors.initials: SC
authors.lastname: Dharmage
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Parkville, Australia.
authors.forename: Lyle C
authors.initials: LC
authors.lastname: Gurrin
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Koplin
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia.
authors.forename: Anne-Louise
authors.initials: AL
authors.lastname: Ponsonby
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Parkville, Australia.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Lowe
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia; Department of Allergy and Immunology, Royal Children's Hospital, Parkville, Australia.
authors.forename: Mimi L K
authors.initials: ML
authors.lastname: Tang
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia; Department of Allergy and Immunology, Royal Children's Hospital, Parkville, Australia.
authors.forename: Dean
authors.initials: D
authors.lastname: Tey
authors.affiliation: Department of Allergy and Immunology, Royal Children's Hospital, Parkville, Australia.
authors.forename: Marnie
authors.initials: M
authors.lastname: Robinson
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Hill
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia.
authors.forename: Helen
authors.initials: H
authors.lastname: Czech
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia.
authors.forename: Leone
authors.initials: L
authors.lastname: Thiele
authors.affiliation: Department of Paediatrics, University of Melbourne, Parkville, Australia; Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Parkville, Australia; European Centre for Environment and Human Health, University of Exeter Medical School, University of Exeter, Truro, United Kingdom.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Osborne
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia; Department of Allergy and Immunology, Royal Children's Hospital, Parkville, Australia; University of Manchester, Manchester, United Kingdom. Electronic address: katie.allen@rch.org.au.
authors.forename: Katrina J
authors.initials: KJ
authors.lastname: Allen
mesh_terms: D002675:Child, Preschool; D021181:Egg Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D004531:Eggs / Q000009:adverse effects; D005260:Female; D000091344:Filaggrin Proteins; D006801:Humans; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D008297:Male; D010641:Phenotype; D011446:Prospective Studies; D012307:Risk Factors; D012882:Skin Tests
chemical_list: C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007073:Immunoglobulin E
keywords: Allergen-specific IgE; Egg allergy; FLG; Filaggrin gene; IQR; Interquartile range; OFC; OR; Odds ratio; Oral food challenge; PPV; Positive predictive value; SPT; Skin prick test; allergen-specific IgE; baked egg; filaggrin; natural history; oral food challenge; resolution; sIgE; skin prick test