Differential Diagnosis for Left Ear Pain
Single most likely diagnosis
- Acute Otitis Externa (AOE): Given the patient's recent history of a cold and the presence of ear pain, mild redness of the tympanic membrane (TM), and swelling of the canal, AOE is the most likely diagnosis. AOE, also known as swimmer's ear, is an infection of the outer ear canal that can be triggered by a viral upper respiratory infection.
Other Likely diagnoses
- Acute Otitis Media (AOM): Although the patient has symptoms more suggestive of AOE, AOM cannot be ruled out without further examination. AOM is an infection of the middle ear that can also follow a viral upper respiratory infection.
- Eustachian Tube Dysfunction (ETD): The patient's recent cold could have led to ETD, causing ear pain and discomfort. However, the presence of canal swelling and redness makes this less likely than AOE.
- Ear Canal Furuncle: A furuncle (boil) in the ear canal could cause pain, redness, and swelling, and could be considered in the differential, especially if the patient has a history of similar episodes or if the examination reveals a localized, painful nodule.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Mastoiditis: Although rare, mastoiditis is a serious complication of AOM that requires prompt recognition and treatment. It presents with ear pain, fever, and signs of mastoid area inflammation.
- Petrous Apicitis: This is a rare but serious infection of the petrous part of the temporal bone, which can occur as a complication of AOM or other infections. It presents with severe ear pain, fever, and neurological symptoms.
- Cavernous Sinus Thrombosis: A potentially life-threatening condition that can arise from facial or sinus infections, including those of the ear. It presents with severe headache, fever, and neurological symptoms.
Rare diagnoses
- Relapsing Polychondritis: A rare autoimmune disorder that can cause cartilage inflammation, including that of the ear. It presents with ear pain, redness, and swelling, but is much less common than infectious causes.
- Necrotizing Otitis Externa: A severe form of AOE that occurs primarily in diabetic or immunocompromised patients, characterized by significant tissue destruction and potential for serious complications.
- Ear Canal Cancer: Although extremely rare, cancer of the ear canal can cause pain, discharge, and swelling. It would be considered in the differential if the patient has risk factors (e.g., history of radiation exposure) or if other diagnoses are ruled out.