Streptomyces albus: a new cause of hypersensitivity pneumonitis.

Hypersensitivity pneumonitis is an immunologic lung disease known to be induced by the inhalation of either organic or inorganic antigens, and it may thus be associated with a variety of occupations and microorganisms. To identify an inciting allergen, environmental, bacteriologic, immunologic, and bronchial challenge studies must be employed. These techniques were used to demonstrate that a bacterium uniformly present in processed dirt, Streptomyces albus, was responsible for a biopsy-proven case of hypersensitivity pneumonitis.