Is bilateral acute otitis media clinically different than unilateral acute otitis media?

BACKGROUND

Information regarding the specific characteristics of bilateral acute otitis media (BAOM) versus unilateral acute otitis media (UAOM) is lacking.

OBJECTIVES

To compare the epidemiologic, microbiologic, and clinical characteristics of BAOM with UAOM in children.

PATIENTS AND METHODS

1026 children aged 3-36 months (61%, <1 year of age) with AOM were enrolled during 1995-2003. All patients had tympanocentesis and middle ear fluid (MEF) culture at enrollment. Clinical status was determined by a clinical/otologic score evaluating severity (0 = absent to 3 = severe, maximal score 12) of patient's fever and irritability and tympanic membrane redness and bulging. Multivariate logistic regression models were used to estimate the risk of BAOM and UAOM presenting with a high severity score (> or =8).

RESULTS

Six-hundred twenty-three (61%) patients had BAOM. Positive MEF cultures were recorded in 786 (77%) patients. More patients with BAOM had positive MEF cultures than patients with UAOM (517 of 623, 83% versus 269 of 403, 67%; P < 0.01). Nontypable Haemophilus influenzae was more common in BAOM than in UAOM (390 of 623, 63% versus 170 of 430, 42%; P < 0.01). Overall, the clinical/otologic score showed higher severity in culture-positive than in culture-negative patients (8.2 +/- 2.0 versus 7.7 +/- 2.2; P < 0.001) and in BAOM than in UAOM (8.3 +/- 2.1 versus 7.8 +/- 2.1; P = 0.001). Clinical/otologic score of > or =8 was more frequent in BAOM than in UAOM patients (371, 61.8% versus 200, 51.3%; P = 0.001). The estimated risk for BAOM patients (compared with UAOM patients) to present with a score > or =8 was 1.5. The association between BAOM and clinical/otologic score > or = 8 was maintained after adjustment for age, previous AOM history, and culture results at enrollment.

CONCLUSIONS

(1) BAOM is frequent; (2) Nontypable H. influenzae is more frequently involved in the etiology of BAOM than of UAOM; (3) The clinical picture of BAOM is frequently more severe than that of UAOM, but overlap of clinical symptoms is common.