title: Timing of solid food introduction in relation to atopic dermatitis and atopic sensitization: results from a prospective birth cohort study.
abstract: OBJECTIVE
  Prophylactic feeding guidelines recommend a delayed introduction of solid foods for the prevention of atopic diseases. Scientific evidence for this is scarce. This study investigates whether a delayed introduction of solids (past 4 months or 6 months) is protective against the development of atopic dermatitis (AD) and atopic sensitization when considering reverse causality.
  
  
  METHODS
  Data from 2612 infants in an ongoing birth cohort study were analyzed at 2 years of age. Information on diet and on symptoms and diagnoses of AD was collected semiannually, and information on specific immunoglobulin E levels was collected at 2 years of age.
  
  
  RESULTS
  Solid food introduction past the first 4 months of life decreased the odds of symptomatic AD but not for doctor-diagnosed AD, combined doctor-diagnosed and symptomatic AD, or atopic sensitization. Postponing the introduction beyond the sixth month of life was not protective in relation to either definition of AD or atopic sensitization. There was also no evidence for a protective effect of a delayed introduction of solids on AD and atopic sensitization in children of atopic parents. There was clear evidence for reverse causality between early skin or allergic symptoms and the introduction of solids.
  
  
  CONCLUSIONS
  This study does not find evidence supporting a delayed introduction of solids beyond the sixth month of life for the prevention of AD and atopic sensitization. We cannot rule out that delaying the introduction of solids for the first 4 months of life might offer some protection. Measures to avoid reverse causality have to be considered in the conduction, analysis, and interpretation of cohort studies on the topic.
authors.affiliation: Institute of Epidemiology, GSF-National Research Center for Environment and Health, Neuherberg, Germany. anne.zutavern@gsf.de
authors.forename: Anne
authors.initials: A
authors.lastname: Zutavern
authors.forename: Inken
authors.initials: I
authors.lastname: Brockow
authors.forename: Beate
authors.initials: B
authors.lastname: Schaaf
authors.forename: Gabriele
authors.initials: G
authors.lastname: Bolte
authors.forename: Andrea
authors.initials: A
authors.lastname: von Berg
authors.forename: Ulrike
authors.initials: U
authors.lastname: Diez
authors.forename: Michael
authors.initials: M
authors.lastname: Borte
authors.forename: Olf
authors.initials: O
authors.lastname: Herbarth
authors.forename: H-Erich
authors.initials: HE
authors.lastname: Wichmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
mesh_terms: D015331:Cohort Studies; D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005512:Food Hypersensitivity / Q000175:diagnosis; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D007225:Infant Food / Q000009:adverse effects; D008297:Male
chemical_list: D007073:Immunoglobulin E