Otitis Media in Infancy: Tympanometric Findings

Abstract

Acute otitis media (AOM) is a common bacterial infection of childhood. Normal infants (91) were followed longitudinally for varying periods from Nov. 1975-April 1977 to assess the correlation between tympanometry and pneumatic otoscopy and to study the pathogenesis of AOM and chronic otitis media early in life. Type A (normal) tympanograms correlated with normal otoscopic findings in 92% of instances. Type B tympanograms, indicating reduced drum compliance with a relatively flat pressure curve, were associated with abnormal otoscopic findings in 93% of cases. The As (reduced compliance, normal pressure) and C (normal compliance, negative pressure) tympanograms were less consistent predictors of otoscopic findings. The correlation of tympanometric and otoscopic findings were similar in infants above and below age 7 mo. Tympanometry provided some insight into the natural history of otitis in 71 infants followed 12-17 mo. Infants who failed to develop otitis had type B curves in 1 of 240 determinations (0.4%). This pattern did not appear in those who developed AOM until the month preceding the 1st attack; 9 of 29 tests (31%) made under these circumstances were type B. When a type B curve appeared in an asymptomatic study infant who had not previously had otitis, AOM developed within 1 mo. in 9 of 10 instances. At the time of diagnosis of 1st AOM, 87% of tympanograms were type B with the remainder type As or C. Of tympanograms obtained from 25 infants during the 6 mo. following 1st AOM, 63% were type B, indicating that abnormal middle ear function was often prolonged. Of these 25, 15 developed recurrent otitis during follow-up.