title: Early exposure to cow's milk protein is protective against IgE-mediated cow's milk protein allergy.
abstract: BACKGROUND
  The diversity in the perceived prevalence, recovery, and risk factors for cow's milk allergy (CMA) necessitated a large-scale, population-based prospective study.
  
  
  OBJECTIVE
  We sought to determine the prevalence, cross-reactivity with soy allergy, and risk factors for the development of CMA.
  
  
  METHODS
  In a prospective study the feeding history of 13,019 infants was obtained by means of telephone interview (95.8%) or questionnaire (4.2%). Infants with probable adverse reactions to milk were examined, skin prick tested, and challenged orally.
  
  
  RESULTS
  Ninety-eight percent of the cohort participated in the study. The cumulative incidence for IgE-mediated CMA was 0.5% (66/13,019 patients). The mean age of cow's milk protein (CMP) introduction was significantly different (P < .001) between the healthy infants (61.6 +/- 92.5 days) and those with IgE-mediated CMA (116.1 +/- 64.9 days). Only 0.05% of the infants who were started on regular CMP formula within the first 14 days versus 1.75% who were started on formula between the ages of 105 and 194 days had IgE-mediated CMA (P < .001). The odds ratio was 19.3 (95% CI, 6.0-62.1) for development of IgE-mediated CMA among infants with exposure to CMP at the age of 15 days or more (P < .001). Sixty-four patients with IgE-mediated CMA tolerated soy, and none had a proved allergy to soy.
  
  
  CONCLUSIONS
  IgE-mediated CMA is much less common than generally reported. Early exposure to CMP as a supplement to breast-feeding might promote tolerance. Finally, soy is a reasonable feeding alternative in patients with IgE-mediated CMA.
authors.affiliation: Allergy and Immunology Institute, Assaf-Harofeh Medical Center, Zerifin, Israel. ykatz49@gmail.com
authors.forename: Yitzhak
authors.initials: Y
authors.lastname: Katz
authors.forename: Nelly
authors.initials: N
authors.lastname: Rajuan
authors.forename: Michael R
authors.initials: MR
authors.lastname: Goldberg
authors.forename: Eli
authors.initials: E
authors.lastname: Eisenberg
authors.forename: Eli
authors.initials: E
authors.lastname: Heyman
authors.forename: Adi
authors.initials: A
authors.lastname: Cohen
authors.forename: Moshe
authors.initials: M
authors.lastname: Leshno
mesh_terms: D000818:Animals; D001942:Breast Feeding; D002417:Cattle; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016269:Milk Hypersensitivity / Q000517:prevention & control*; D008894:Milk Proteins / Q000276:immunology*; D011446:Prospective Studies; D012307:Risk Factors; D013025:Glycine max / Q000276:immunology
chemical_list: D008894:Milk Proteins; D007073:Immunoglobulin E