title: Season of birth and childhood food allergy in Australia.
abstract: BACKGROUND
  Recent studies suggest a possible role for low ultraviolet radiation exposure and low vitamin D status as a risk factor for food allergy. We hypothesized that children born in autumn/winter months (less sun exposure) might have higher food allergy rates than those born in spring/summer.
  
  
  METHODS
  We compared IgE-mediated food allergy rates by season of birth in 835 children aged 0-4 yr assessed 1995-2009 in a specialist referral clinic, using population births as controls. To address potential concerns about generalizability, we also examined national prescriptions for adrenaline autoinjectors (2007) and infant hypoallergenic formula (2006-2007).
  
  
  RESULTS
  Although live births in the general ACT population showed no seasonal pattern (50% autumn/winter vs. 50% spring/summer), autumn/winter births were more common than spring/summer births among food allergy patients (57% vs. 43%; p < 0.001). The same seasonal pattern was observed with peanut (60% vs. 40%; p < 0.001) and egg (58% vs. 42%; p = 0.003). Regional UVR intensity was correlated with relative rate of overall food allergy (β, -1.83; p = 0.05) and peanut allergy (β, -3.27; p = 0.01). National data showed that autumn/winter births also were more common among children prescribed EpiPens (54% vs. 46%; p < 0.001) and infant hypoallergenic formula (54% vs. 46%; p < 0.001).
  
  
  CONCLUSIONS
  The significantly higher rates of food allergy in children born autumn/winter (compared to spring/summer), the relationship between relative food allergy rates and monthly UVR, combined with national adrenaline autoinjector and infant hypoallergenic formula prescription data, suggest that ultraviolet light exposure/vitamin D status may be one of many potential factors contributing to childhood food allergy pathogenesis.
authors.affiliation: John James Medical Centre, Deakin, ACT, Australia. rmullins@allergycapital.com.au
authors.forename: Raymond James
authors.initials: RJ
authors.lastname: Mullins
authors.forename: Sunday
authors.initials: S
authors.lastname: Clark
authors.forename: Constance
authors.initials: C
authors.lastname: Katelaris
authors.forename: Victoria
authors.initials: V
authors.lastname: Smith
authors.forename: Graham
authors.initials: G
authors.lastname: Solley
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
mesh_terms: D001315:Australia / Q000453:epidemiology; D002675:Child, Preschool; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012621:Seasons