SEASONAL OCCUPATIONAL ASTHMA IN AN AGRICULTURAL PRODUCTS MERCHANT - ACASE-REPORT

A 52-year-old agricultural products merchant reported mild occupationa l asthma and rhinitis throughout the year, with severe asthma from Feb ruary to May. He had been exposed to various substances, particularly grain, insecticides, fungicides, and fertilizers over 35 years. We ide ntified a castor-bean-containing fertilizer as the cause of the diseas e by skin prick test and bronchial provocation test. Specific IgE agai nst castor bean was detected by enzyme allergosorbent test, and protei ns with mel. mass of less than 14.4 kDa and masses of 15.5, 29.5, and 30.5 kDa were identified as allergens by Western blot analysis. The se asonal character of symptoms could be explained by a more frequent use of the fertilizer during spring. Six months after avoidance of the al lergen, the patient reported chronic bronchitis without asthma. Occupa tional allergy to castor bean should be considered in subjects with se asonal asthma and exposure to ''natural'' fertilizers.