title: Allergy in children in hand versus machine dishwashing.
abstract: OBJECTIVE
  The hygiene hypothesis stipulates that microbial exposure during early life induces immunologic tolerance via immune stimulation, and hence reduces the risk of allergy development. Several common lifestyle factors and household practices, such as dishwashing methods, may increase microbial exposure. The aim of this study was to investigate if such lifestyle factors are associated with allergy prevalence.
  
  
  METHODS
  Questionnaire-based study of 1029 children aged 7 to 8 years from Kiruna, in the north of Sweden, and Mölndal, in the Gothenburg area on the southwest coast of Sweden. Questions on asthma, eczema, and rhinoconjunctivitis were taken from the International Study of Asthma and Allergies in Childhood questionnaire.
  
  
  RESULTS
  Hand dishwashing was associated with a reduced risk of allergic disease development (multivariate analysis, odds ratio 0.57; 95% confidence interval: 0.37-0.85). The risk was further reduced in a dose-response pattern if the children were also served fermented food and if the family bought food directly from farms.
  
  
  CONCLUSIONS
  In families who use hand dishwashing, allergic diseases in children are less common than in children from families who use machine dishwashing. We speculate that a less-efficient dishwashing method may induce tolerance via increased microbial exposure.
authors.affiliation: Paediatric Allergology, Queen Silvia Children's Hospital, Gothenburg, Sweden; Västra Götaland Healthcare Department, Follow-up and Analysis Unit, Gothenburg, Sweden; Department of Paediatrics, University of Gothenburg, Gothenburg, Sweden; and bill.hesselmar@vgregion.se.
authors.forename: Bill
authors.initials: B
authors.lastname: Hesselmar
authors.affiliation: Västra Frölunda Paediatric Outpatient Clinic, Västra Frölunda, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Hicke-Roberts
authors.affiliation: Paediatric Allergology, Queen Silvia Children's Hospital, Gothenburg, Sweden; Department of Paediatrics, University of Gothenburg, Gothenburg, Sweden; and.
authors.forename: Göran
authors.initials: G
authors.lastname: Wennergren
mesh_terms: D001331:Automation; D002648:Child; D005260:Female; D063373:Hand Hygiene; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012915:Soaps / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology
chemical_list: D012915:Soaps
keywords: allergy; asthma; child; eczema; risk factors