Mechanisms of otitis media development. Involvement of neurogenic inflammation.

The mucosal lining of the middle ear cavity, in particular that of the tympanic membrane and its pars flaccida, exhibits a number of sensory nerves containing the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP). The mucosa is not only rich in nerves and blood vessels but also contains numerous mast cells. It is possible that interactions between histamine-containing mast cells and SP-containing and CGRP-containing nerves--neurogenic inflammation--is one of the mechanisms involved in vessel permeability changes in otitis media with effusion.