Occupational asthma and IgE sensitization in a pharmaceutical company processing psyllium.

We assessed the prevalence of occupational asthma and IgE sensitization to psyllium in a pharmaceutical company producing psyllium hydrophilic mucilloid, which is used as a laxative. Workers were intermittently exposed, approximately 5 times/yr, for periods of less than 10 days. Of the 140 employees, 130 (93%) were studied before a processing period via a questionnaire spirometry (n = 125), blood sampling (n = 118), and skin prick tests (n = 120) with 7 common inhaled allergens as well as plantain and psyllium. Thirty-nine workers had a history suggestive of occupational asthma. Twenty-three of 120 (19%) showed a skin wheal diameter greater than or equal to 3 mm to psyllium and 31 of 118 (26%) had increased specific IgE antibodies; 39 (32%) workers had at least 1 of these 2 features. Subjects with a questionnaire suggestive of asthma or occupational asthma were further investigated by serial monitoring of peak expiratory flow rates and PC20 methacholine before and during the psyllium processing period. All workers had spirometry repeated during the processing period. Twenty-one subjects who had a PC20 less than or equal to 16 mg/ml (n = 10) and/or decreased their PC20 by a greater than or equal to 3.2-fold difference (n = 4) and/or changed their FEV1 by greater than or equal to 10% (n = 13) during the processing period were referred for inhalation challenges to psyllium in the laboratory. Five of the 18 workers for whom these tests were feasible gave an immediate bronchoconstrictive reaction.(ABSTRACT TRUNCATED AT 250 WORDS)