THE CLINICAL SPECTRUM OF HUMIDIFIER DISEASE IN SYNTHETIC-FIBER PLANTS

In a synthetic fiber production site with recirculating cold water hum idification systems and small-size-particle (> 0.1 mu < 1 mu) oil mist exposure, humidifier disease was diagnosed in several workers. The pa tients could be divided into three groups illustrating the clinical sp ectrum of humidifier disease: humidifier fever (toxic inhalation fever ) (12 patients); an asthma-like syndrome (8 patients); and allergic al veolitis (4 patients). Natural challenge at the work place, monitored by parameters such as peak-flow, spirometry, blood leucocyte count, an d body temperature, provided important diagnostic information. In pati ents with chronic allergic alveolitis, a gradual recovery during an ex posure-free period indicated a work-related causation, more than chang es during challenge in normal work. In some patients, the fungus Sporo thrix schenckii, hitherto unknown as a sensitizer, may have been at le ast one of the causative antigens. Measured levels of viable fungi (le ss than or equal to 100 CFU/m(3)) and endotoxin (64 pg/m(3)) in air sa mples were much lower than those at which health effects usually are r eported. Small-size-particle oil mist exposure may have underestimated the exposure to microorganisms, but otherwise an adjuvant role to thi s type of co-exposure might also be postulated. In contrast to allergi c alveolitis, the asthma-like syndrome appeared to be more common in p atients with a history of atopy and of smoking. (C) 1997 Wiley-Liss, I nc.