Bronchial Hyperresponsiveness and Level of Exposure in Occupational Asthma due to Western Red Cedar (Thuja plicata): Serial Observations before and after Development of Symptoms

Four workers from a cedar sawmill who developed red cedar asthma are described. They had serial measurements of lung function and nonspecific bronchial hyperresponsiveness (NSBH) several years before and after the development of chest symptoms. Measurements of dust concentration and specific IgE antibodies to plicatic acid-human serum albumin (PA-HSA) conjugate were also carried out before the onset of disease. NSBH developed in parallel with...