Original Contribution
The American Journal of Gastroenterology (2006) 101, 1005–1011; doi:10.1111/j.1572-0241.2006.00526.x
Investigating the Hygiene Hypothesis as a Risk Factor in Pediatric Onset Crohn's Disease: A Case-Control Study
Devendra K Amre MD, PhD1,2, Philippe Lambrette MSc2, Liliane Law BSc2, Alfreda Krupoves MD3, Virginie Chotard PhD2, Florin Costea MD2, Guy Grimard MD, FRCP1,4, David Israel MD, FRCP5, David Mack MD6 and Ernest G Seidman MD, FRCP2,7
- 1Department of Paediatrics, University of Montreal, Montreal, Canada
- 2Research Centre, Sainte-Justine Hospital, Montreal, Canada
- 3Department of Preventive and Social Medicine,University of Montreal, Montreal, Canada
- 4Division of Orthopedics, Department of Pediatrics, University of Montreal, Montreal, Canada
- 5Division of Gastroenterology,British Columbia's Children's Hospital, Vancouver, Canada
- 6Division of Gastroenterology, Children's Hospital of Eastern Ontario, Ottawa, Canada
- 7Division of Gastroenterology, McGill University Health Center, Montreal, Canada
Correspondence: Devendra K Amre, MD, PhD, Department of Paediatrics, University of Montreal, Research Center, Bureau A-728, Ste-Justine Hospital, 3175 Cote-Sainte-Catherine, Montreal, Quebec, Canada H3T 1C5.
Received 1 September 2005; Accepted 30 November 2005.
Abstract
BACKGROUND AND OBJECTIVES:
Evidence for the hygiene hypothesis in the etiology of Crohn's disease (CD) is unclear. We investigated the relationship between infection-related exposures and risk for CD in children.
METHODS:
A hospital-based case-control was carried out. Newly-diagnosed cases of CD (n = 194), less than 20 yr of age were recruited from the gastroenterology clinic of a large-pediatric inflammatory bowel disease (IBD) center in Montreal, Canada. Orthopedic patients pair-matched (n = 194) for timing of diagnosis and area of residence were recruited as controls. Information on infection-related exposures between birth and disease diagnosis was ascertained by administering a structured questionnaire to the mother and the index subject. The relationship between the frequency and timing of infection-related exposures with CD was studied.
RESULTS:
The mean age (SD) at diagnosis was 12.3 (5.1). CD was more common after 10 yr of age. Gender distribution was similar between comparison groups. In multivariate conditional logistic regression, family history of IBD (odds ratio (OR) = 4.6; 95% confidence interval (CI) = 1.6–13.3), age (OR = 1.2; 95% CI = 1.1–1.3), and owning a pet (OR = 2.0; 95% CI = 0.9–4.5) were associated with risk for CD, whereas regular use of a personal towel (OR = 0.5; 95% CI = 0.2–0.9) and lesser crowding in homes (OR = 0.3; 95% CI = 0.1–0.8) were protective. Day-care attendance during the first 6 months of life and "physician-diagnosed infections" between 5 and 10 yr of age were associated with increased risks for CD.
CONCLUSIONS:
Infection-related exposures seem to enhance risk for CD in children. The timing of these exposures during early childhood may be relevant to the etiology of pediatric CD.
