Based on Rebecca's signs and symptoms, what is the most appropriate diagnosis?

Bilateral acute otitis media is a common diagnosis in pediatric patients characterized by the presence of fluid in the middle ear that is often accompanied by inflammation. This diagnosis is particularly appropriate if Rebecca presents with symptoms such as ear pain, irritability, and fever, along with physical examination findings that reveal bulging or erythematous tympanic membranes.

Acute otitis media often follows a viral upper respiratory infection, where the infections from the upper respiratory tract can lead to blockage in the eustachian tubes, creating an environment for bacteria to proliferate. In contrast, viral upper respiratory infections usually present initially with nasal congestion, cough, and other upper respiratory symptoms without the specific ear symptoms that would suggest otitis media.

While sinus infections can also lead to ear symptoms, they typically present with significant sinus congestion, facial pain, or purulent nasal discharge, as opposed to the more localized ear-focused symptoms in otitis media. Allergic rhinitis, characterized by sneezing, nasal itching, and clear rhinorrhea, lacks the acute pain and fever associated with acute otitis media. Therefore, if Rebecca demonstrates a clear combination of ear pain along with systemic signs like fever, the diagnosis of bilateral acute otitis media is the most fitting.