title: Decompensation of pollen-induced asthma in two towns with different pollution levels in La Mancha, Spain.
abstract: BACKGROUND
  Allergic diseases have increased in industrialized countries and this increase is associated not only with genetic factors but also with lifestyle and environmental factors such as air pollution. Our hypothesis was that asthma in pollen-allergic patients from two towns with very different pollution levels in La Mancha (Spain) could be affected to a very different degree.
  
  
  OBJECTIVE
  Our objectives were to assess the risk factors associated with decompensation of pollen-induced asthma in the two towns and to perform a comparison between the patients from Puertollano (high pollution level) and Ciudad Real (low pollution level) with respect to daily symptoms, medication used and peak-flow measurements.
  
  
  METHODS
  We designed a cohort study with 137 patients (66 from Puertollano and 71 from Ciudad Real), conducted over 3 years (1999-2001) and including two pollen seasons. The two populations presented similar demographic and clinical characteristics. The variables studied included: area of residence, sex, age, smoking status, asthma symptoms and positive prick tests. Clinical decompensation was monitored by symptoms recorded on diary cards, twice daily peak-flow measurements and the use of protocolized medication.
  
  
  RESULTS
  There was a clinically relevant relationship between the place of residence and clinical decompensation. The risk of clinical decompensation in patients from Puertollano was up to three times higher than that of patients in Ciudad Real (P=0.034). Furthermore, patients from Puertollano and patients with moderate asthma presented more rapid decompensation compared with patients from Ciudad Real (P=0.020) and patients with mild asthma (P=0.049).
  
  
  CONCLUSIONS
  In conclusion, pollen-allergic asthmatics in Puertollano present a poorer clinical course and become decompensated earlier than those from Ciudad Real and it could be due to air pollution.
authors: Allergy Unit, Hospital Santa Bárbara, Puertollano, and Department of Mathematics, Universidad Autónoma, Barcelona, Spain. pilarmurgimeno@saludalia.com
authors: P
authors: P
authors: Mur Gimeno
authors: F
authors: F
authors: Feo Brito
authors: C
authors: C
authors: Martínez
authors: A
authors: A
authors: Tobías
authors: L
authors: L
authors: Suárez
authors: F
authors: F
authors: Guerra
authors: P A
authors: PA
authors: Galindo
authors: E
authors: E
authors: Gómez
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000485:Allergens / Q000009:adverse effects*; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage; D001249:Asthma / Q000188:drug therapy / Q000209:etiology*; D004334:Drug Administration Schedule; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011058:Pollen / Q000009:adverse effects*; D012111:Residence Characteristics; D012720:Severity of Illness Index; D012882:Skin Tests; D012907:Smoking / Q000009:adverse effects
chemical_list: D000393:Air Pollutants; D000485:Allergens; D018927:Anti-Asthmatic Agents