What is the condition characterized by fluid build-up behind the ear and leads to conductive hearing loss?

The condition characterized by fluid build-up behind the ear that leads to conductive hearing loss is non-suppurative otitis media. This condition occurs when the middle ear becomes inflamed, often due to an infection or blockage in the Eustachian tube, causing fluid to accumulate without the presence of pus. This fluid buildup can interfere with the normal movement of the eardrum and the bones of the middle ear, resulting in conductive hearing loss.

In this context, suppurative otitis media, which involves pus or purulent fluid, is an acute form of infection and may lead to different symptoms and treatment approaches, but it typically does cause pain and fever rather than being solely characterized by fluid build-up. Conversely, otitis externa refers to inflammation of the outer ear canal, while tympanosclerosis involves the thickening or scarring of the eardrum, which may result from perforation or repeated infections. None of these other conditions specifically aligns with the description of fluid accumulation behind the ear leading to conductive hearing loss.