Establishing clinical and immunologic criteria for diagnosis of occupational immunologic lung disease with phthalic anhydride and tetrachlorophthalic anhydride exposures as a model.

Using a questionnaire and serum antibody studies, we evaluated 13 workers exposed to phthalic anhydride (PA) and tetrachlorophthalic anhydride (TCPA). The questionnaire was designed to identify symptoms compatible with anhydride-induced immunologic or irritant syndromes. Specific IgG and IgE for both PA-human serum albumin (PA-HSA) and TCPA-HSA were determined by enzyme-linked immunosorbent assay in two different laboratories. In addition, 11 workers had cutaneous testing with PA-HSA and TCPA-HSA, and nine workers were interviewed. One worker was found to have PA-associated asthma and rhinitis. We conclude that a questionnaire and serologic assays for specific IgG and IgE are helpful to identify workers who have or are at risk for developing occupational immunologic lung disease such as those induced by anhydrides. However, additional evaluation may be necessary in those workers with such diseases as intrinsic asthma that may be difficult to differentiate from occupational immunologic lung disease.