Plasma component of middle ear effusion evaluated by prekallikrein level.

Plasma leakage into middle ear was evaluated by the level of prekallikrein in middle ear effusions (MEE), measured by the fluorometric assay. Plasma leakage into middle ear is a major source of MEE, especially serous effusions. The degree of plasma leakage at the time of sampling is very low in mucoid effusions and varied in serous effusions. Active plasma leakage into middle ear would occur at the early restricted inflammatory phase in the middle ear.