Secretory otitis media--a question of surface activity in the eustachian tube?

An improved thin-layer chromatographic assay for monitoring phospholipid ratio in mucus was used to study the respiratory system distribution of children with and without secretory otitis media. Phosphatidylcholine, phosphatidylethanolamine and sphingomyelin abound, while only traces of other phospholipids are found. Analyses show more sphingomyelin and less phosphatidylcholine in the Eustachian tube and nose than in the lung, while phosphatidylethanolamine has about the same distribution. The phosphatidylcholine/sphingomyelin ratio is significantly less in Eustachian tube mucus from children with secretory otitis media compared with otologically healthy children, which indicates a different secretory pattern of the cells in the Eustachian tube of these children. The distribution of phospholipids in middle ear secretion is different from the distribution obtained from the Eustachian tube in children with secretory otitis media thus verifying a clearance 'blocking' of the tube caused by the disease.