A case of occupational asthma caused by Japanese cedar wood dust

Abstract

Inhalation of wood dust can cause immediate and/or late onset asthma, and the number of differeut kinds of wood responsible for such reactions is increasing. We report a patient with asthma induced by exposure to the dust of Japanese cedar wood (Cryptomeria japonica). A 30-year-old man developed rhinorrhea, sneezing and coughing, 6 years prior to admission. For the past 8 years, he had been involved in interior decoration of kitchen and sauna room using wood. Total peripheral eosinophil count was 600/㎣ and serum total IgE level was 505 IU.ml. Allergy skin prick test showed negative responses to 80 common inhalant and food allergens. Skin prick test to Japanese cedar wood dust extract showed negative respinse. Bronchoprovocation test with Japanese cedar wood dust extract (1:10w/v) showed dual asthmatic response. Specific IgE and IgG4 antibodies to Japanese cedar wood dust extract were not detectable by ELISA. Serum neutrophil chemotactic assay using patient's serum collected during bronchoprovocation test showed increased neutrophil chemotactic activity at 4 hr. In conclusion, non-IgE mediated mechanism may be involved in pathogenesis of Japanese cedar wood dust-induced asthma. Further studies will be needed to investigate the pathogenetic mechanism.