Occupational asthma caused by champignon flies

Background: Occupational bronchial asthma in mushroom (champignon) workers is unusual, although reports on it appeared in 1938 and 1951; we have not f ound any others since those dates. Here we report the case of a 52-year-old man who works as a champignon cultivator. He suffered rhinoconjunctivitis and asthma attacks whenever he entered the champignon culture caves. We stu died flies as a possible antigen source. We collected these insects from th e growing sites in order to identify them, and then prepare an extract; the samples turned out to be of two families of insects of the order Diptera, 98% from the Phoridae family (Brachycera suborder) and 2% from the Sciarida e (Nematocera suborder). Methods: Skin prick tests, conjunctival provocation tests, serum specific I gE, specific IgE-binding fractions in immunoblotting, and monitoring of PEF R (at work and off work) were performed. Results: IgE-mediated hypersensitivity to these flies was demonstrated by s kin prick test, conjunctival provocation test, serum specific IgE, and IgE- binding fractions in immunoblotting. Monitoring of PEFR both at work and of f work showed a clear relationship between symptoms, or fall in PEFR, and t he workplace. Conclusions: We report the case of a patient suffering from asthma and rhin oconjunctivitis caused by hypersensitivity to fly proteins.