Occupational asthma from exposure to rye flour in a Japanese baker

Three years after beginning employment at a bakery, a 32‐year‐old Japanese man began experiencing acute asthma exacerbations after exposure to rye flour. Antigen‐specific serum IgE antibodies were detected to the albumin and globulin, gliadin, prolamin, and glutenin protein fractions of rye flour purified from the crude antigen, but only to the albumin and globulin fraction of wheat flour. The histamine concentration producing one‐half maximal effect was lower for all four rye flour fractions than for the wheat flour fractions. After inhalation of the albumin and globulin fraction of rye flour, forced expiratory volume in 1 sec decreased to 77.7% of that pre‐provocation. To our knowledge, this is the first report of baker's asthma due to rye flour in Japan. Baker's asthma is caused by inhalation of cereal flours and is a common occupational allergic disease in Europe and the United States, where bread is a staple food. Here, we present the first report of baker's asthma caused by exposure to rye flour in a Japanese baker in Japan.