What is often present in otitis media with effusion?

Otitis media with effusion is characterized primarily by the presence of fluid accumulation in the middle ear. This condition can occur without the acute symptoms commonly associated with other forms of otitis media, such as pain and fever, which are more indicative of an active infection. While the other options might present in different types of ear infections or conditions, fluid accumulation is the hallmark of otitis media with effusion.

Specifically, in this condition, the fluid can hinder the transmission of sound and lead to hearing difficulties, but the key defining feature is the effusion itself. This fluid may not always lead to significant symptoms like drainage or acute pain, which differentiates it from other types of otitis media where these symptoms are more pronounced. Therefore, the presence of fluid accumulation is what firmly establishes the diagnosis of otitis media with effusion.