Final answer:
Otitis media is an infection of the middle ear that often follows a URI, showing redness and stiffness of the tympanic membrane. It is associated with symptoms like ear pain and fluid buildup, and is particularly common in young children.
Step-by-step explanation:
An infection of the middle ear that usually follows an upper respiratory infection (URI) and presents with redness and stiffness of the tympanic membrane is known as otitis media. This condition, also termed acute otitis media (AOM), is particularly common in children and is a significant cause of medical consultations and antibiotic prescriptions. AOM is characterized by symptoms such as ear pain (otalgia), fever, nausea, vomiting, and in infants, nonverbal signs like ear tugging or rubbing. Fluid buildup behind the tympanic membrane due to eustachian tube swelling often leads to increased pressure, resulting in inflammation, and can progress to a bulging or even torn tympanic membrane if left untreated.
In contrast, otitis externa is an infection of the external ear canal, sometimes referred to as swimmer's ear, and otitis interna (or labyrinthitis) affects the inner ear. Tinnitus, meanwhile, is a symptom of underlying conditions like hearing loss or ear injury, characterized by ringing or noises in the ears, not an infection.