Acute Otitis Media (AOM): This is the most common cause of ear infection and fever, especially in children. AOM is characterized by inflammation of the middle ear, often due to bacterial infection, and is frequently accompanied by fever, ear pain, and sometimes discharge.

Otitis Externa: An infection of the outer ear canal, often caused by bacterial or fungal pathogens. It can present with fever, especially if the infection is severe or spreading.
Upper Respiratory Tract Infection (URTI): While not exclusively an ear infection, URTIs can lead to ear discomfort or secondary ear infections (like AOM) and are often accompanied by fever.
Sinusitis: Inflammation of the sinuses can cause fever and may lead to or exacerbate ear infections due to the shared Eustachian tube drainage pathway.

Mastoiditis: A serious complication of AOM where the infection spreads to the mastoid bone. It requires prompt recognition and treatment to prevent severe complications, including intracranial infections.
Labyrinthitis: Inflammation of the inner ear, which can be caused by infection. It's less common but can lead to severe vertigo, hearing loss, and other complications if not properly managed.
Petrous Apicitis: A rare but serious infection of the petrous part of the temporal bone, which can lead to severe neurological complications if missed.

Relapsing Fever: Caused by certain bacteria (e.g., Borrelia), this condition can present with recurring episodes of fever and might be accompanied by ear symptoms in some cases, though it's less directly associated with ear infections.
Autoimmune Inner Ear Disease: A rare condition where the immune system attacks the inner ear, leading to symptoms that might include fever, vertigo, and hearing loss.
Ear Involvement in Systemic Diseases: Certain systemic diseases (e.g., Kawasaki disease, autoimmune disorders) can have ear manifestations, including infection and fever, though these are less common presentations.