Background: The literature indicates that early exposure to children in the family and to day care permanently influences the development of allergic disease. A study was undertaken to examine the associations of family size and day care with adult asthma and hay fever and to determine whether these associations are mediated through specific IgE production and whether they vary with allergic predisposition.
Methods: 18 530 subjects aged 20–44 years from 36 areas predominantly in the market economies participated in the European Community Respiratory Health Survey and provided information through interviewer-led questionnaires. 13 932 subjects gave blood samples for measurement of specific IgE.
Results: Hay fever was less common in subjects with many siblings (OR=0.92; 95% CI 0.90 to 0.95 per sib). There was a U-shaped relationship between asthma and number of siblings (quadratic effect of siblings, pwheeze=0.014, pFEV1=0.016). In subjects without siblings but exposed to children in day care, hay fever was less common (OR=0.76; 95% CI 0.60 to 0.98) and asthma symptoms were more common (ORwheeze=1.48; 95% CI 1.12 to 1.95). Adjustment for specific IgEs did not alter these associations. The inverse association of hay fever with siblings was found in sensitised subjects (OR=0.89; 95% CI 0.84 to 0.94) and in those with parental allergy (OR=0.91; 95% CI 0.85 to 0.97), but not in subjects without such a predisposition (OR=1.02; 95% CI 0.97 to 1.09).
Conclusion: Subjects exposed to many children at home or in day care experienced less hay fever and more asthma in adulthood. Microbial challenge through children may contribute to a non-allergic immunological development giving less hay fever but more airways infections predisposing to asthma. These effects were not mediated through production of specific IgE. The protective effect of siblings on hay fever was particularly strong in those with an allergic predisposition.
- hygiene hypothesis
- hay fever
Statistics from Altmetric.com
Coordinating centre (London): P Burney, S Chinn, C Luczynska, D Jarvis, E Lai.
Project Management Group: P Burney (project leader), S Chinn, C Luczynska, D Jarvis, P Vermeire (Antwerp), H Kesteloot (Leuven), J Bousquet (Montpellier), D Nowak (Hamburg), the late J Prichard (Dublin), R de Marco (Verona), B Rijcken (Groningen), J M Anto (Barcelona), J Alves (Oporto), G Boman (Uppsala), N Nielsen (Copenhagen), P Paoletti (Pisa).
Participating centres: Austria: W Popp (Vienna); Australia: M Abramson, J Raven, J Rolland (Melbourne);Belgium: P Vermeire, F van Bastelaer (Antwerp South, Antwerp Central); Estonia: R Jögi (Tartu); France: J Bousquet, J Knani (Montpellier), F Neukirch, R Liard (Paris), I Pin, C Pison (Grenoble), A Taytard (Bordeaux); Germany: H Magnussen, D Nowak (Hamburg), H E Wichmann, J Heinrich (Erfurt); Greece: N Papageorgiou, P Avarlis, M Gaga, C Marossis (Athens); Iceland: T Gislason, D Gislason (Reykjavik); Ireland: J Prichard, S Allwright, D MacLeod (Dublin); Italy: M Bugiani, C Bucca, C Romano (Turin), R de Marco Lo Cascio, C Campello (Verona), A Marinoni, I Cerveri, L Casali (Pavia); Netherlands: B Rijcken, A Kremer (Groningen, Bergen-op-Zoom, Geleen); New Zealand: J Crane, S Lewis (Wellington, Christchurch, Hawkes Bay); Norway: A Gulsvik, E Omenaas (Bergen); Portugal: J A Marques, J Alves (Oporto); Spain: J M Antó, J Sunyer, F Burgos, J Castellsagué, J Roca, J B Soriano, A Tobías (Barcelona),N Muniozguren, J Ramos González, A Capelastegui (Galdakao),J Castillo, J Rodriguez Portal (Seville), J Martinez-Moratalla, E Almar (Albacete), J Maldonado Pérez A Pereira, J Sánchez (Huelva), J Quiros, I Huerta, F Pavo (Oviedo); Sweden: G Boman, C Janson, E Björnsson (Uppsala), L Rosenhall, E Norrman, B Lundbäck (Umeå), N Lindholm, P Plaschke (Göteborg); Switzerland: U Ackermann-Liebrich, N Künzli, A Perruchoud (Basel); UK: M Burr, J Layzell (Caerphilly), R Hall (Ipswich), B Harrison (Norwich), J Stark (Cambridge); USA: S Buist, W Vollmer, M Osborne (Portland).
The following grants helped to fund the local studies: Australia: Allen and Hanbury’s, Australia; Belgium: Belgian Science Policy Office, National Fund for Scientific Research; France: Ministére de la Santé, Glaxo France, Institut Pneumologique d’Aquitaine, Contrat de Plan Etat-Région Languedoc-Rousillon, CNMATS, CNMRT (90MR/10, 91AF/6), Ministre delegué de la santé, RNSP; Germany: GSF and the Bundesminister für Forschung und Technologie, Bonn; Greece: Greek Secretary General of Research and Technology, Fisons, Astra and Boehringer-Ingelheim; India: Bombay Hospital Trust; Italy: Ministero dell’Università e della Ricerca Scientifica e Tecnologica, CNR, Regione Veneto grant RSF n. 381/05.93; New Zealand: Asthma Foundation of New Zealand, Lotteries Grant Board, Health Research Council of New Zealand; Norway: Norwegian Research Council project no 101422/310; Portugal: Glaxo Farmacêutica Lda, Sandoz Portugesa; Spain: Ministero Sanidad y Consumo FIS grants #91/0016060/00E-05E and #93/0393 and grants from Hospital General de Albacete, Hospital General Juan Ramón Jiménenz, Consejeria de Sanidad Principado de Asturias; Sweden: Swedish Medical Research Council, Swedish Heart Lung Foundation, Swedish Association against Asthma and Allergy; Switzerland: Swiss National Science Foundation grant 4026-28099; UK: National Asthma Campaign, British Lung Foundation, Department of Health, South Thames Regional Health Authority; USA: United States Department of Health, Education and Welfare Public Health Service grant #2 S07 RR05521-28.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.