Abstract

Bronchorrohea has been defined as a condition in which more than 100 ml of sputum is produced within 24 hours, an amount in excess of that seen in chronic lung diseases. The rheological and chemical characteristics of the sputum are here described. Levels of viscosity, dry weight, N-acetyl neuraminic acid (NANA), fucose, and sulphate fall between those in saliva and mucoid sputum from chronic lung diseases. These levels were always higher in bronchorrhoea sputum than in saliva and therefore may be used in the differential diagnosis of bronchorrhoea and hypersalivation. Bronchorrhoea sputum has the constituents of a bronchial secretion but is low in acid glycoprotein. Certain other features are commonly found - a large amount of froth, increase in viscosity with time, and separation into two phases. Some cases respond to steroids, particularly when the levels of NANA in the sputum are low.