title: The influence of sun exposure in childhood and adolescence on atopic disease at adolescence.
abstract: BACKGROUND
  It has been postulated that ultraviolet ray exposure in childhood might influence the development of allergic disease. We examined whether reported sun exposure during childhood or in adolescence is related to the occurrence of atopy or allergic disease.
  
  
  METHODS
  Population-based longitudinal cohort study with sixteen-year follow-up (N = 415). Subjects were recruited at birth as part of an infant health study. The reported daily duration of sun exposure in the summer months was recorded at 8 and 16 yrs of age. Allergen sensitization and the presence of eczema, asthma, and rye grass positive rhinitis were recorded at age 16.
  
  
  RESULTS
  Reported sun exposures of more than 4 h per day during summer holidays in adolescence were associated with reduced eczema and rhinitis but not inhalant allergen sensitization or asthma risk. Thus, higher sun exposure during summer holidays and summer weekends in adolescence was associated with significantly reduced eczema (test of trend p-value = 0.001 summer holidays; test of trend p-value = 0.003 summer weekends) and rye grass positive rhinitis (test of trend p-value = 0.03 summer holidays; test of trend p-value = 0.02 summer weekends). Sun exposure at adolescence or age 8 was not related to inhalant allergen sensitization. There was no association between serum 25(OH)D levels at adolescence with either inhalant allergen sensitization or allergic disease and adjustment for serum 25(OH)D levels did not alter these findings.
  
  
  CONCLUSIONS
  Increased sun exposure during summer holidays in adolescence was associated with reduced eczema and rhinitis risk, independently of measured vitamin D levels but no difference in inhalant allergen sensitization or asthma. The beneficial effects of sun exposure on allergic disease may operate independently from vitamin D or an effect on allergen sensitization.
authors.affiliation: Murdoch Children's Research Institute, Melbourne, Vic., Australia. andrew.kemp1@bigpond.com.au
authors.forename: Andrew Stewart
authors.initials: AS
authors.lastname: Kemp
authors.forename: Anne-Louise
authors.initials: AL
authors.lastname: Ponsonby
authors.forename: Angela
authors.initials: A
authors.lastname: Pezic
authors.forename: Jennifer Ann
authors.initials: JA
authors.lastname: Cochrane
authors.forename: Terence
authors.initials: T
authors.lastname: Dwyer
authors.forename: Graeme
authors.initials: G
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000276:immunology; D002648:Child; D015331:Cohort Studies; D004485:Eczema / Q000453:epidemiology / Q000276:immunology*; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007231:Infant, Newborn; D008129:Lolium; D008297:Male; D011058:Pollen / Q000009:adverse effects / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology / Q000276:immunology*; D012882:Skin Tests; D013472:Sunlight / Q000009:adverse effects; D014807:Vitamin D / Q000097:blood
chemical_list: D000485:Allergens; D014807:Vitamin D; D007073:Immunoglobulin E
keywords: atopy; eczema; sun exposure; vitamin D