Effect of penicillin on formation of fibrous adhesions in acute otitis media.

Fibrous middle ear adhesions are occasionally encountered in middle ear surgery and may cause a hearing impairment. Although usually associated with chronic otitis media, adhesions are also found following a single episode of experimental acute suppurative otitis media, suggesting a pathogenesis based on the inflammatory process engaging acute infection. In a well-established rat model of pneumococcal acute otitis media, we report on the effect of penicillin V on formation of fibrous middle ear adhesions. Previous studies have shown marked impact of penicillin on mucosal goblet cell density and other histopathologic features. Number, anatomic localization, and histopathologic morphology of adhesions were assessed in a longitudinal study of 25 normal, 25 untreated, and 25 treated rats. Although penicillin administration induced a slight tendency toward fewer ears with adhesions and fewer adhesions per ear, these changes were nonsignificant. Histomorphology and the general pattern of anatomic localization of adhesions were unaffected by penicillin administration. We conclude that administration of penicillin has an inconspicuous effect on the formation of fibrous adhesions in experimental acute otitis media caused by Streptococcus pneumoniae.