Prognosis and endotoxin contents in middle ear effusions in cases after acute otitis media.

We analysed the endotoxin content of middle ear effusion (MEE) from patients after acute otitis media, by a Limulus assay. Endotoxin was positive in 70% of the cases treated with antibiotics at an acute event for more than 5 days, while the incidence of bacteria was only 22%. One month after the sample collection, cases with a high concentration of endotoxin in MEE still tended to have effusion. These results suggest that endotoxin in MEE cannot be easily inactivated and may be involved in the development of acute otitis media into chronic otitis media with effusions.