Occupational hypersensitivity lung disease.

A case of occupational hypersensitivity pneumonitis caused by an air conditioning unit is presented. Aspergillus fumigatus and aureobasidium pullulans were cultured from this unit and antibodies to these organisms were found the patient's blood. The case shows that this disease may present in a very subtle form and may be diagnosed by a culture from the patient's environment and an easily performed blood precipitin test. The importance of searching for this type of lung disease and the need for obtaining precipitin tests are stressed.