Immunological and respiratory changes in coffee workers.

Immunological status and respiratory function were studied in a group of 45 coffee workers. Skin tests with coffee allergens demonstrated the highest percentage of positive reactions to dust collected during emptying bags (40.0%), followed by dust of green (12%) and then roasted coffee (8.9%). Among 34 skin-tested control workers, 14.7% had positive skin reaction to dust collected during emptying bags, but none had positive skin reaction to green or roasted coffee. Serum levels of total IgE were increased in 24.4% of coffee workers and in 5.9% of control subjects. The prevalence of all chronic respiratory symptoms was significantly higher in coffee workers than in control subjects. Coffee workers with positive skin tests to coffee allergen had a significantly higher prevalence of chronic cough (63.6%) and chronic phlegm (72.7%) than those with negative skin tests (32.4% and 23.5% respectively). There was a significant mean decrease over the Monday work shift in the maximum expiratory flow rate at 50% of vital capacity (MEF50: -7.9%) and at 25% vital capacity (MEF25: -17.8%), suggesting an obstructive effect mostly in smaller airways. Coffee workers with positive skin tests to coffee allergens had larger acute reductions in flow rates than those with negative skin tests but the difference was not statistically significant.