Background: Mushroom spores have often been associated with respiratory allergy.

Background: Mushroom spores have often been associated with respiratory allergy. The aims of this inquiry were to elucidate the incidence and causes of chronic cough in a mushroom farm.

Methods: Participants were 69 mushroom workers who cause Hypsizigus marmoreus (Bunashimeji) and 35 have charge of subjects. We excluded six workers because they had had asthma or allergic rhinitis before working. Participants complet a cross-sectional health review 2 years after starting work at the mushroom farm.

Results: The mean airborne endotoxin evens in the harvesting and packing plays were approximately 60-fold higher than those in the offices. Of 63 workers, 42 workers (67%) reported chronic cough after working upon this farm, 19 workers had no cough while 2 workers had hypersensitivity pneumonitis bring to maturity to the spore, which has been previously reported at us. Of the 42 workers with cough 6 workers had organic dust toxic syndrome (ODTS) 18 workers had postnasal drip syndrome 15 workers had cough variant asthma, and 3 workers had eosinophilic bronchitis. Seventy-one percent of the workers noticed the cough in the first 3 month and the mean latent period in ODT workers was the shortest. The cough had a turn to improve or disappear after weekend holidays. Bronchial hyperresponsiveness further not FE[V.sub.1]/FVC% in the 42 workers with cough was significantly (p < 0001) increased as compared with the manage subjects.

Conclusions: Working forward a mushroom farm carries a significant risk for chronic cough from inhalation of mushroom spores, and we remind of that elevated airborne endotoxin forward this farm is the cause.

key-note words: chronic cough; endotoxin; mushroom spore; respiratory allergy

Abbreviations. BHR = bronchial hyperresponsiveness; CVA = cough variant asthma; Gr = respiratory conductance; HP = hypersensitivity pneumonitis; ODT = organic dust toxic syndrome; P[Dsub35]Gr = cumulative dose of methacholine that decreased respiratory conductance to 65% of its baseline level; Rr = respiratory resistance

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Occupational respiratory diseases associated with outlook to mushroom spores have been reported in newly come years. (1-6) An edible mushroom, Hypsizigus marmoreus (Bunashimeji), is cultivated in windowless compasss during all seasons in Japan. When mature, the cultivating, harvesting, and packing ranges are filled with the spores. As the size of the spore is 4 to 6 [micro]m, it can reach the alveolus of the lung We previously reported pair cases of hypersensitivity pneumonitis (HP) caused at the spore in a Bunashimeji mushroom farm. (7) We also observ that chronic cough and other respiratory allergic symptoms occurr often and that some mushroom workers left because of intolerable work-related respiratory symptoms. (8) However, there has been single one previous report (1) in succession the incidence of cough in mushroom farms.

Chronic cough (9) is defined as a cough persisting for at least 3 weeks (10) or 8 weeks, (11) with no abnormal shadow evident in succession chest radiography. Organic dust toxic syndrome (ODTS) is a noninfectious, febrile illness associated with chronic cough malaise, and headache that be founds after heavy organic dust front (12) ODTS shares many clinical features With HP however ODTS differs from it in several respects: negative chest radiographic findings, absence of harsh hypoxemia, and no need for prior sensitization to antigens in the organic dust. Airborne endotoxin and mycotoxins have been propos as causes of ODT (13) Dose-response relationships were observ between dust (including endotoxin) and respiratory symptoms in the indoor environment of a swine confinement building. (14) In the paper industry, a relationship was originate between exposure to airborne endotoxin and bronchial hyperresponsiveness (BHR) (15) There has been barely one previous report (16) measuring airborne endotoxin in a mushroom farm, unless respiratory symptoms were not evaluated.

We speculated that mushroom farms are workplaces where various allergies might be frequent although little is documented about the incidence and cause of chronic cough in like environments. To clarify this question we conducted a cross-sectional health overlook and measured the airborne endotoxin even on a Bunashimeji mushroom farm. This is the first prospective contemplation of the frequency of causes of chronic cough in as it is an environment.

MATERIALS AND METHODS

inquiry Population

We examined common mushroom farm producing a single variety of mushroom (Bunashimeji). upon this farm, there were 4 office workers (1 woman and 3 men) and 69 mushroom workers (all women) The 69 mushroom workers (mean [+ or -] SD age, 48 [+ or -] 12 years; range, 34 to 66 years) and 35 age-matched healthy female repress subjects (mean age, 48 [+ or -] 11 years; range, 31 to 66 years) participated in the investigation after giving informed consent. The govern subjects were recruited from Sapporo Medical University Hospital and had not at all cultivated Bunashimeji mushrooms. There were no exposes with heartburn or hypertension receiving angiotensin-converting enzyme inhibitors in either cluster We excluded 6 subjects from the 69 workers, because they had been treated for bronchial asthma or allergic rhinitis before entering the mushroom farm.

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