Elevated serum IgE, eosinophilia, and lung function in rubber workers

We previously reported an outbreak of acute respiratory illness associated with eosinophilia in a group of rubber workers who performed a thermoinjection process in which synthetic rubber was heated and then injected onto metal molds. This study was conducted to determine if persistent respiratory health effects were associated with this work area and to explore the possible allergic etiology of this syndrome. A survey was performed 1 mo after a major improvement in area ventilation and consisted of baseline, cross-shift, and cross-week spirometry; diffusing capacity; serum immunoglobulin E (IgE), total eosinophil count; and skin patch testing. Baseline lung function, cross-shift, and cross-week spirometry were not significantly worse in the exposed group as compared to the control group. However, either eosinophilia (greater than 450/mm3) or elevated serum IgE (greater than 470 ng/ml) were present in 44% of exposed workers vs. 11% of the control group (p = .003). Nine months later, neither eosinophilia nor elevated IgE were associated with employment in this work area. We conclude that employment in the thermoinjection process was associated with eosinophilia and elevated IgE, which suggests sensitization to one of the components of the rubber, although no effect on pulmonary function could be demonstrated.