Within the past few years it has been definitely demonstrated that asthmatic conditions may be caused not only by pollens, horse hair, dander, etc., but also by any particular protein substances that may be inhaled and undergo parenteral absorption. Not the least important of these foreign proteins are those due to the spores of fungi. While it has long been recognized that fungi may cause pathologic conditions in the lungs, still the literature is relatively meager as regards the part played by their spores alone.
Recently Castellani, Stoval, Reich and Fox have stressed the clinical importance of mycology as applied to clinical medicine, but the allergic aspect of the subject has not been especially emphasized by these men.
While asthma itself as caused from the inhalation of animal proteins (horse asthma, pollen asthma, hay fever) is an old subject, the allergic aspect is of relatively recent origin. Especially is this
TOWEY JW, SWEANY HC, HURON WH. SEVERE BRONCHIAL ASTHMA APPARENTLY DUE TO FUNGUS SPORES FOUND IN MAPLE BARK. JAMA. 1932;99(6):453–459. doi:10.1001/jama.1932.02740580021005