In a patient with a constant sense of pressure in the right ear and air-fluid levels detected, which condition is most likely present based on the history?

The presence of a constant sense of pressure in the right ear, along with the detection of air-fluid levels, strongly suggests a dysfunctional or obstructed Eustachian tube. This condition can commonly lead to what is referred to as Eustachian tube dysfunction. When the Eustachian tube is not functioning properly, it fails to equalize pressure between the middle ear and the external environment, leading to a sensation of fullness or pressure in the ear.

The detection of air-fluid levels indicates that there may be a collection of fluid in the middle ear space, which is often a result of Eustachian tube blockage. This blockage can be caused by various factors such as infection, allergies, or structural anomalies.

In the context of the choices provided, while acute otitis media could also present with similar symptoms due to fluid accumulation in the middle ear due to infection, the specific mention of air-fluid levels typically aligns more closely with Eustachian tube dysfunction. Chronic sinusitis and seasonal allergy exacerbation could lead to symptoms affecting the ear but would not usually present with air-fluid levels on examination.

Thus, the combination of the patient's symptoms and examination findings points strongly toward Eustachian tube dysfunction as the most likely condition present.