Tests for sensitisation in occupational medicine practice - the soy bean example

Abstract

Objective: To determine the prevalence of sensitisation to soy bean measured by specific IgE and skin prick tests (SPTs) and to examine the association between evidence of sensitisation to soy bean allergens and symptoms of allergic disease. Design: Cross-sectional study. Questionnaire survey. A venous blood sample was taken for specific IgE testing, and SPTs for common allergens.and soy bean dust were performed. Setting: Soy bean mill. Participants: A volunteer sample of 22 workers exposed to soy bean dust; the first 20 non-exposed workers presenting to the National Centre for Occupational Health clinic formed the control group. Main outcome measure: Immunological tests for sensitisation and symptoms of respiratory and allergic disease. Results: Eight of the exposed workers had positive skin reactions to either full-fat or defatted soy bean. None of the controls was SPT-positive, Eight of the exposed workers had increased levels of soy-specific IgE of whom only 4 were SPT-positive and had an increased level of soy-specific IgE. One of the control workers had an increased level of soy-specific IgE. Workers with an increased specific IgE or SPT positive to soy bean did not have more symptoms than workers with negative tests. However, work-related breathlessness was significantly higher in the exposed group (P < 0,05). Conclusions: The data suggest that the immunological tests for sensitisation were not useful in identifying workers with soy bean-related disease but that tests for sensitisation were linked to exposure.

S Afr Med J 1995; 85: 522-525