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5194251 
Journal Article 
Occupational Asthma Induced by Chrysonilia sitophila in the Logging Industry 
Tarlo, SM; Wai, Y; Dolovich, J; Summerbell, R 
1996 
Yes 
Journal of Allergy and Clinical Immunology
ISSN: 0091-6749
EISSN: 1097-6825 
97 
6 
The development of occupational asthma caused by repeated exposure to Chrysonilia-sitophila was examined. The patient worked in the logging industry and had over a 5 year history of work related, asthmatic symptoms. Fungal cultures used to coat wood were subcultured and confirmed to be C-sitophila. To test for immunoglobulin-E (IgE) antibodies to C-sitophila, blood serum samples and C-sitophila extracts were incubated on cyanogen-bromide treated discs. Skin prick tests (SPTs) were performed on the case patient and on a survey of 93 additional patients. The patient elicited a positive SPT to fungal spores and a negative SPT to wood extracts. The patient reacted positively to SPTs with dilute and pure C-sitophila, with wheal diameters of 8 and 6 millimeters, respectively. When incubated with C-sitophila, the patient's serum exhibited 13.4% binding, a value greater than that observed in the serum of atopic and nonatopic controls. The patient's forced expiratory volume in 1 second (FEV1) was 104% of the predicted value. The provocative concentration of methacholine eliciting a 20% decline in the FEV1 (PC20) was 0.015mg/ml, suggesting severe hyperresponsiveness. Peak flow increased after work and decreased during work. After 4 weeks away from work, the FEV1 increased to 112% of the predicted value and the PC20 increased to 2.57mg/ml. The patient was diagnosed with occupational asthma and his duties were adjusted. Of the 93 patients in the clinical survey, 16% reacted positively to C-sitophila. The positive patients were significantly more likely to be asthmatic and atopic than those who reacted negatively. The authors conclude that C-sitophila is the likely cause and IgE mediation the likely mechanism of this patient's occupational asthma. Exposure to C-sitophila should be regarded as a risk factor for occupational asthma.