However otitis media with effusion often has no symptoms .
然而,并积液的中耳炎通常没有症状。
Not all cases of otitis external respond well to treatment .
不是所有外耳炎的病例对治疗都有良好效应。
Ear infection , or otitis media , is the most frequently diagnosed illness in u.s. children younger than 15 and the leading cause of emergency room visits by children , according to background information in the news release .