title: Impact of meteorological variation on hospital visits of patients with tree pollen allergy.
abstract: BACKGROUND
  Climate change could affect allergic diseases, especially due to pollen. However, there has been no epidemiologic study to demonstrate the relationship between meteorological factors, pollen, and allergic patients. We aimed to investigate the association between meteorological variations and hospital visits of patients with tree pollen allergy.
  
  
  METHODS
  The study subjects were adult patients who received skin prick tests between April and July from 1999 to 2008. We reviewed the medical records for the test results of 4,715 patients. Patients with tree pollen allergy were defined as those sensitized to more than 1 of 12 tree pollen allergens. We used monthly means of airborne tree pollen counts and meteorological factors: maximum/average/minimum temperature, relative humidity, and precipitation. We analyzed the correlations between meteorological variations, tree pollen counts, and the patient numbers. Multivariable logistic regression analyses were used to investigate the associations between meteorological factors and hospital visits of patients.
  
  
  RESULTS
  The minimum temperature in March was significantly and positively correlated with tree pollen counts in March/April and patient numbers from April through July. Pollen counts in March/April were also correlated with patient numbers from April through July. After adjusting for confounders, including air pollutants, there was a positive association between the minimum temperature in March and hospital visits of patients with tree pollen allergy from April to July(odds ratio, 1.14; 95% CI 1.03 to 1.25).
  
  
  CONCLUSIONS
  Higher temperatures could increase tree pollen counts, affecting the symptoms of patients with tree pollen allergy, thereby increasing the number of patients visiting hospitals.
authors: Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Youngtong-gu, Suwon, South Korea.
authors: Si-Heon
authors: SH
authors: Kim
authors: Hae-Sim
authors: HS
authors: Park
authors: Jae-Yeon
authors: JY
authors: Jang
mesh_terms: D000328:Adult; D000393:Air Pollutants; D000485:Allergens / Q000009:adverse effects / Q000276:immunology; D057231:Climate Change / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data* / Q000639:trends; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008685:Meteorological Concepts; D052638:Particulate Matter; D011058:Pollen / Q000009:adverse effects / Q000276:immunology; D056910:Republic of Korea; D012621:Seasons; D012882:Skin Tests; D014197:Trees / Q000009:adverse effects / Q000276:immunology
chemical_list: D000393:Air Pollutants; D000485:Allergens; D052638:Particulate Matter