Background: The role of soybean dust as a causal agent of asthma has been clearly established since the Barcelona asthma epidemics in the 1980s. The large number of patients who were first seen with asthma symptoms during those epidemics provided an excellent opportunity to study the possibilities of different diagnostic tests.
Objective: This study was designed to evaluate the usefulness of the skin test and amplified ELISA technique for quantifying specific IgE in the diagnosis of soybean asthma.
Patients and results: Ninety epidemic asthmatic patients and 95 nonepidemic asthmatic patients were studied 2 years after the last epidemic. Results of prick tests and ELISAs for specific IgE with hull and dust extracts showed a significant difference between the two groups of patients (p < 0.001). Sensitivity and specificity of glycerinated prick test with hull extract in epidemic asthmatic patients were 57.7% and 95.3%, respectively, and ELISA values were 56.6% and 93.7%, respectively. Similar results were obtained with dust extracts.
Conclusion: Glycerinated skin prick tests and ELISAs with soybean hull and dust extracts have proved effective in the diagnosis of soybean asthma, even 2 years after the epidemics. Taking into account the sensitivity (90.5%) and specificity (93.7%) of ELISA test results for epidemic asthmatic patients found when the epidemic occurred, data from this study suggest that both tests may be very useful for the diagnosis of soybean dust-induced asthma.