Table 5

Selected features of cases of probable occupational asthma#

CasesAge yrsSexAsthma+W‐R RSFEV1 L·min−1PC20 mg·mL−1
1st follow-up2nd follow-upBaselineFollow-upBaselineFollow-up
135FNoNoneCough, wheezing, chest-tightness2.131.844.90.92
322MNoChest-tightnessCough, chest-tightness5.115.11>328.9
434FNoNoneCough, chest-tightness3.083.14>3215.5
522MNoNoneCough, chest-tightness5.574.82>324.0
620MYesNoneCough, wheezing3.723.4111.03.5
  • W‐R: welding-related

  • RS: respiratory symptoms

  • FEV1: forced expiratory volume in one second

  • PC20: provocative concentration causing a 20% fall in the FEV1

  • F: female

  • M: male

  • #: cases include subjects that developed at least one W‐R RS suggestive of occupational asthma at first follow-up that persisted until the second follow-up or the development of at least one W‐R RS as of the second follow-up with a two-fold or a ≥3.2‐fold decrease in PC20 between the baseline and end of study

  • +: physician-diagnosed asthma at baseline

  • n=6