Effect of penicillin on experimental acute otitis media - A histopathological study of goblet cell density, bone modelling dynamics, polyp and adhesion formation

Clinical studies have shown that the effect of antibiotic treatment on acut e otitis media is modest. Experimental acute otitis media induces a number of histopathological changes in the middle ear mucosa. Among these are incr eased goblet cell density, polyp and adhesion formation, as well as massive osteoneogenesis. To investigate the effect of penicillin administration on these histopathological features, we employed a rat model of acute pneumoc occal otitis media. Five of 25 rats were sacrificed on days 4, 8, 16, 90 an d 180 post-inoculation, preceded by oral administration of penicillin V 100 mg/kg/day, initiated on day 2 and lasting 5 days. Using a light microscope , qualitative and quantitative histopathology of middle ear goblet cell den sity, bone-modelling dynamics, polyp and adhesion formation was registered and compared with previous studies of untreated animals. Increase in goblet cell density and new bone formation was reduced significantly by treatment , whereas polyp and adhesion formation was unaffected by penicillin adminis tration. It is concluded that penicillin reduces middle ear secretory capac ity and new bone formation during and following acute otitis media. conceiv ably preventing subsequent development of secretory otitis media, leaving p olyp and adhesion formation unchanged.