Background: The results of recent studies suggest that factors in rural environments may protect against the development of allergic diseases, but the underlying mechanisms are not well understood. The aim of this study was to investigate the prevalence of allergic diseases, to establish if this prevalence is influenced by migration from rural to urban areas and to identify environmental risk factors associated with these diseases. Methods: A cross-sectional study of children aged 9–12 years from a rural village, a rural town and an urban city in Korea was conducted. Demographic and disease-related information was obtained via a detailed questionnaire, and skin prick tests were performed. Results: There were significant differences in lifestyle and environmental factors between children from the rural village, the rural town and the urban children. The prevalence of allergic diseases and atopy was higher in urban children. A lower prevalence of allergic diseases and atopy was associated with farming parents, contact with farm animals during pregnancy, owning pets or a stable, breast-feeding and having older siblings. A comparison of rural village and rural town children revealed no evidence of an association of allergic diseases and atopy with farming parents, contact with farm animals during pregnancy or owning a stable. On the other hand, having older siblings and antibiotic use during infancy were significantly associated with allergic diseases and atopy in these children. Conclusions: Protective factors associated with a farming environment and/or rural lifestyle may influence the prevalence of allergic diseases and atopy in Korean children.

Keywords:
Allergic disease, Atopy, Farming, Hygiene hypothesis, Rural lifestyle
1.
Hong SJ, Lee MS, Sohn MH, Shim JY, Hahn YS, Park KS, et al: Self reported prevalence and risk factors of asthma among Korean adolescents: 5-year follow-up study, 1995–2000. Clin Exp Allergy 2004;34:1556–1562.
2.
Strachan DP: Hay fever, hygiene and household size. Br Med J 1989;299:1259–1260.
3.
Braun-Fahrlander C, Riedler J, Herz U, Eder W, Waster M, Grize L, et al: Environmental exposure to endotoxin and its relation to asthma in school-age children. N Engl J Med 2002;347:869–877.
4.
Addo Yobo EO, Custovic A, Taggart SC, Asafo-Agyei AP, Woodcock A: Exercise induced brochospasm in Ghana: difference in prevalence between urban and rural schoolchildren. Thorax 1997;52:161–165.
5.
Barnes M, Cullinan P, Athanasaki P, MacNeill S, Hole AM, Harris J, et al: Crete: does farming explain urban and rural differences in atopy? Clin Exp Allergy 2001;31:1822–1828.
6.
Riedler J, Braun-Fahrlander C, Eder W, Schreuer M, Waser M, Maisch S, et al: Exposure to farming in early life and development of asthma and allergy: a cross-sectional survey. Lancet 2001;358:1129–1133.
7.
Klintberg B, Berglund N, Lilja G, Wickman M, van Hage-Hamsten M: Fewer allergic respiratory disorders among farmer’s children in a closed birth cohort from Sweden. Eur Respir J 2001;17:1151–1157.
8.
Downs SH, Marks GB, Mitakakis TZ, Leuppi JD, Car NG, Peat JK: Having lived on a farm and protection against allergic diseases in Australia. Clin Exp Allergy 2001;31;570–575.
9.
Alder A, Tager I, Quintero DR: Decreased prevalence of asthma among farm-reared children compared with those who are rural but not farm-reared. J Allergy Clin Immunol 2005;115:67–73.
10.
Waser M. von Mutius E, Riedler J, Nowak D, Maisch S, Carr D, et al: Exposure to pets, and the association with hay fever and asthma among children of farmers. Clin Exp Allergy 2000;30:194–200.
11.
Platts-Mills TA, Erwin E, Heymann P, Woodfolk J: Is the hygiene hypothesis still a viable explanation for the increased prevalence of asthma? Allergy 2005;60(suppl 79):25–31.
12.
Perzanowski MS, Miller RL, Thorne PS, Barr RG, Divjan Sheares BJ, et al: Endotoxin in inner-city homes: associations with wheeze and eczema in early childhood. J Allergy Clin Immunol 2006;117:1082–1089.
13.
Filipiak B, Heinrich J, Schafer T, Ring J, Wichmann HE: Farming, rural lifestyle and atopy in adults from southern Germany – results from the MONICA/KORA study Augsburg. Clin Exp Allergy 2001;31:1829–1838.
14.
Alm JS, Swartz G, Lilja G, Scheynius A, Pershagen G: Atopy in children of families with an anthroposophic lifestyle. Lancet 1999;353:1485–1488.
15.
Viinanen A, Munhbayarlah S, Zevgee T, Narantsetseg L, Naidansuren TS, Koskenvuo M, et al: The protective effect of rural living against atopy in Mongolia. Allergy 2007;62:272–280.
16.
Kim JS, Ouyang F, Pongracic JA, Fang Y, Wang B, Liu X, et al: Dissociation between the prevalence of atopy and allergic disease in rural China among children and adults. J Allergy Clin Immunol 2008;122:929–935.
17.
Ma Y, Zhao J, Han ZR, Chen Y, Leung TF, Wong G: Very low prevalence of asthma and allergies in schoolchildren from rural Beijing, China. Ped Pulmonol 2009;44:793–799.
18.
Asher MI, Keil U, Anderson HR, Beasley R, Crane J, Martinez F, et al: International Study of Asthma and Allergies in Childhood (ISAAC): rationale and methods. Eur Respir J 1995;8:482–491.
19.
Von Ehrenstein OS, Von Mutius E, Illi S, Baumann L, Bohm O, Von Kries R: Reduced risk of hay fever and asthma among children of farmers. Clin Exp Allergy 2000;30:187–193.
20.
Nystad W, Magnus P, Roksund O, Svidal B, Hetlevik O: The prevalence of respiratory symptoms and asthma among school children in three different areas of Norway. Pediatr Allergy Immunol 1997;8:35–40.
21.
Kaur B, Anderson HR, Austin J, Burr M, Harkins LS, Strachan DP, et al: Prevalence of asthma symptoms, diagnosis, and treatment in 12–24 year old children across Great Britain (International Study of Asthma and Allergies in Childhood, ISAAC UK). BMJ 1998;316:118–124.
22.
Braback L, Breborowicz A, Dreborg S, Knutsson A, Pieklik H, Bjorksen B: Atopic sensitization and respiratory symptoms among Polish and Swedish school children. Clin Exp Allergy 1994;24:826–835.
23.
Campello C, Ferrari M, Poli A, Olivieri M, Tardivo S, Verlato G: Prevalence of asthma and asthma like symptoms in an adult population sample from Verona. ECHRS Verona European Community Respiratory Health Survey. Monaldi Arch Chest Dis 1998;53:505–509.
24.
Turkeltaub PC, Gergen PJ: Prevalence of upper and lower respiratory conditions in the US population by social and environmental factors: data from the second National Health and Nutrition Examination Survey. 1976–80 (NHANES II). Ann Allergy 1991;67:147–154.
25.
Crane J: Comparison of findings from the ISAAC written and video questionnaires on asthma symptoms (abstract). Eur Resp J 1996;9:230s.
26.
Steinman HA, Donson H, Kawalski M, Toerien A, Potter PC: Bronchial hyper-responsiveness and atopy in urban, peri-urban and rural South African children. Pediatr Allergy Immunol 2003;14:383–393.
27.
Seiskari T, Kondrashova A, Viskari H, Kaila M, Haapala AM, Aittoniemi J, et al: Allergic sensitization and microbial load – a comparison between Finland and Russian Karelia. Clin Exp Allergy 2007;148:47–52.
28.
Kramer MS, Matush L, Bogdanovich N, Dahhou M, Platt RW, Mazer B: The low prevalence of allergic disease in Eastern Europe. Clin Exp Allergy 2009;39:708–716.
29.
Matricardi PM, Franzinelli F, Franco A, Caprio G, Murru F, Cioffi D, et al: Sibship size, birth order, and atopy in 11,371 Italian young men. J Allergy Clin Immunol 1998;101:439–444.
30.
Braun-Fahrlander C, Gassner M, Grize L, Leu U, Sennhauser FH, Varonier HS, et al: Prevalence of hay fever and allergic sensitization in farmers’ children and their peers living in the same rural community. SCARPOL team. Swiss Study on Childhood Allergy and Respiratory Symptoms with Respect to Air Pollution. Clin Exp Allergy 1999;29:28–34.
31.
Gehring U, Strikwold M, Schram-Bijkerk D, Weinmayr G, Grnunet J, Nagel G, et al: Asthma and allergic symptoms in relation to house dust endotoxin: ISAAC II. Clin Exp Allergy 2008;38:1911–1920.
32.
Riedler J, Eder W, Obserfeld G, Schreuer M: Austrian children living on a farm have less hay fever, asthma and allergic sensitization. Clin Exp Allergy 2000;30:194–200.
33.
Alm JS, Swartz J, Lilja G, Scheynius A, Pershagen G: Atopy in children of families with an anthroposophic lifestyle. Lancet 1999;353:1485–1488.
34.
Hooper R, Calvert J, Thompson RL, Deetlefs ME, Burney P: Urban/rural differences in diet and atopy in South Africa. Allergy 2008;63:425–431.
© 2012 S. Karger AG, Basel
2012
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.