title: Small nonspecialized farming as a protective factor against immediate-type occupational respiratory allergy?
abstract: BACKGROUND
  In Poland small, nonspecialized farms, growing different crops and raising usually a few animals of various species constitute the majority.
  
  
  OBJECTIVE
  The aim of the case-control study was to evaluate the risk factors of work-related respiratory symptoms and occupational asthma and/or rhinitis in Polish farmers and investigate whether the farming characteristics may have influence on the prevalence of atopy and allergic diseases.
  
  
  METHODS
  The study groups comprised 100 cases who were farmers reporting work-related asthmatic and/or rhinitis symptoms from randomly selected family doctors practices (80 of 353) and 102 healthy controls. All subjects were examined by means of a questionnaire, skin prick tests (SPT) to common and occupational allergens, total serum immunoglobulin (Ig)E level and the presence of specific IgE and allergen-specific inhalation challenge tests were performed. The provocation tests were monitored with the spirometry, histamine challenge test and evaluation of nasal symptoms score and nasal washings.
  
  
  RESULTS
  Respiratory allergic disease was recognized in 68 symptomatic patients, including 41 cases because of occupational allergens (asthma n=38, rhinitis n=41). Step-wise logistic regression analysis confirmed the protective role of small farms against the development of work-related symptoms (OR 0.23; 95% CI 0.11, 0.47) as well as the significance of positive SPT to cereals (OR 5.55; 95% CI 1.6, 19.21) and storage mites (OR 3.73; 95% CI 1.27, 10.96) as a risk factor of these symptoms. Cereal farming (OR 13.75; 95% CI 2.39, 78.83) and positive SPT to cereals (OR 26.92; 95% CI 5.33, 135.9) and storage mites (OR 44.07; 95% CI 8.40, 231.1) were found to be significant risk factors of occupational asthma and/or rhinitis.
  
  
  CONCLUSIONS
  Cereal farming and hypersensitivity to cereals plays the significant role in the development of occupational asthma among Polish farmers. It also seems that working on small farms may protect farmers against work-related respiratory symptoms that are mostly because of allergy.
authors.affiliation: Department of Occupational Diseases & Occupational and Environmental Allergy Centre, Lodz, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Walusiak
authors.forename: P
authors.initials: P
authors.lastname: Krawczyk-Adamus
authors.forename: W
authors.initials: W
authors.lastname: Hanke
authors.forename: T
authors.initials: T
authors.lastname: Wittczak
authors.forename: C
authors.initials: C
authors.lastname: Pałczyński
mesh_terms: D000382:Agricultural Workers' Diseases / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D000485:Allergens / Q000009:adverse effects*; D000818:Animals; D001985:Bronchial Provocation Tests; D016022:Case-Control Studies; D002523:Edible Grain / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008925:Mites / Q000276:immunology; D016273:Occupational Exposure; D011044:Poland / Q000453:epidemiology; D012130:Respiratory Hypersensitivity / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D012307:Risk Factors; D012424:Rural Population; D012882:Skin Tests; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens