Occupational asthma due to cleaning agents

Objectives: To assess the pattern of bronchial responses to cleaning agents during specific inhalation challenges (SICs) in subjects with cleaning-related asthma symptoms at work. Methods: A retrospective review of 44 subjects who completed a SIC with the cleaning/disinfecting products suspected of causing work-related asthma. Results: Challenge exposure to cleaning agents elicited a ≥20% fall in FEV 1 in 17 (39%) subjects. The products that induced a positive SIC contained quaternary ammonium compounds (n=10), glutaraldehyde (n=3), both of these agents (n=1), and ethanolamines (n=2). Positive SICs were associated with a significant decrease in the median (interquartile range) value of the provocative concentration of histamine causing a 20% fall in FEV 1 (PC 20 ) from 1.4 (0.2-4.2) mg/ml at baseline to 0.5 (0.4-3.0) mg/ml after the challenge and a significant increase in sputum eosinophils from 1.8 (0.8-7.2)% at baseline to 10.0 (4.1-15.9)% 7 hours after the challenge exposure while these parameters did not significantly change in subjects with a negative SIC. Overall, 11 of the 17 subjects with positive SICs showed either a >3-fold decrease in post-challenge histamine PC 20 value, a >2% increase in sputum eosinophils, or both of these outcomes. Conclusions: These data indicate that a substantial proportion of workers who experience asthma symptoms related to cleaning materials show a pattern of bronchial reaction consistent with sensitizer-induced occupational asthma. The results also suggest that quaternary ammonium compounds are the principal cause of sensitize-induced OA among cleaners.