title: Nasal mucosal histamine reactivity among teachers six years after working in a moisture-damaged school.
abstract: OBJECTIVE
  The objective of this study was to determine whether verified increased nasal mucosal reactivity among teachers, who had been working in a school with severe moisture problems, still persisted 6 years after remedial measures had been taken. The increased nasal mucosal reactivity, measured as the mucosal swelling reaction upon histamine provocation, had earlier been shown both 1 and 3 years after the renovation.
  
  
  METHODS
  Twenty-four teachers in the target school and sixteen teachers in the control school, who participated in all the investigations (1995, 1997 and 2000), answered a standardized questionnaire and underwent a nasal histamine provocation test. In addition to the registration of mucosal swelling, the microcircular reaction to histamine provocation was measured with laser-Doppler flowmetry.
  
  
  RESULTS
  The nasal histamine reactivity among the teachers, measured as the mucosal swelling reaction, was no longer increased. However, the laser-Doppler flowmetry showed that the teachers in the target school had significantly divergent microcircular perfusion (P = 0.0022) and a concentration of moving blood cells (P=0.0009) in the histamine provocation when compared with the teachers in the control school; this finding indicates more-pronounced plasma leakage and edema from the nasal mucosa.
  
  
  CONCLUSIONS
  Restored nasal histamine reactivity, measured as mucosal swelling reaction, was observed among the teachers 6 years after an obviously successful renovation of the school environment. However, changes in microcirculation indicate a remaining effect on the nasal mucosa.
authors.affiliation: Department of Otorhinolaryngology, Orebro University Hospital, SE-701 85 Orebro, Sweden. stig.rudblad@orebroll.se
authors.forename: Stig
authors.initials: S
authors.lastname: Rudblad
authors.forename: Kjell
authors.initials: K
authors.lastname: Andersson
authors.forename: Lennart
authors.initials: L
authors.lastname: Bodin
authors.forename: Göran
authors.initials: G
authors.lastname: Stridh
authors.forename: Jan-Erik
authors.initials: JE
authors.lastname: Juto
mesh_terms: D005178:Faculty; D006632:Histamine; D006801:Humans; D006813:Humidity / Q000009:adverse effects*; D006967:Hypersensitivity / Q000175:diagnosis / Q000209:etiology / Q000473:pathology; D017078:Laser-Doppler Flowmetry; D009297:Nasal Mucosa / Q000473:pathology*; D009299:Nasal Provocation Tests; D016273:Occupational Exposure / Q000009:adverse effects*; D012574:Schools; D012882:Skin Tests
chemical_list: D006632:Histamine