[Lipoperoxidation in otorrhea of the middle ear as a marker of infection. Clinical application].

If the generation of free oxygen radicals is a pathophysiological finding in middle-ear infections, as has been reported, demonstration of the oxidative consequences of free radicals in middle-ear exudates may be a quick, simple, objective and accessible test for quantifying the degree of mucosal injury. Therefore, samples of the discharge fluid from cases of acute otitis media (n = 17), cholesteatoma (n = 17), chronic discharge in the absence of cholesteatoma (n = 10), and secretory otitis media (n = 15) were tested using an enzymatic colorimetric assay for lipid peroxide levels due to superoxide and hydroxyl radicals during infection. Lipid peroxide levels in acute otitis media, cholesteatoma, and chronic discharge without cholesteatoma ranged from 575 to 650 nmol/mg of exudate, and was 67 nmol/mg in secretory otitis media, which were statistically significant findings. Infectious otitis media showed findings secondary to increased oxidative metabolism, but not secretory otitis media. Measurement of this oxidative metabolism could serve to monitor the evolution of episodes, as well as to detect relapse or reinfection, and to evaluate response to new therapeutic options for suppurative otitis, such as topical antioxidants.