Otitis media with effusion. Cytological and microbiological correlates.

A quantitative cytologic study of 83 middle ear effusions from children with otitis media with effusion (OME) was made with the use of cytocentrifuge-prepared smears and was correlated with bacteriological findings. The identification of the types of cell present in an effusion was confirmed by electron microscopic findings. The most common cell types were neutrophilic leukocytes, lymphocytes, and macrophages, but a few eosinophils were found in only one case. The cytologic profile of an effusion correlated well with the bacterial culture results. Neutrophil counts were significantly higher in effusions that contained pathogenic bacteria (P less than .01) than in culture-negative effusions. Lymphocytes were the dominant cell type in culture-negative effusions. The results support the idea that bacteria are involved in the pathogenesis of many cases of OME.