Differential Diagnosis
- Single most likely diagnosis
- A) Acute otitis media: The patient's symptoms of ear pain, a red and bulging eardrum, and an immobile eardrum are classic signs of acute otitis media. The recent history of swimming in a lake may have contributed to the development of the infection, but the presentation is more consistent with acute otitis media than with an external ear infection.
- Other Likely diagnoses
- E) Otitis externa: Although the ear canal appears normal and there is no pain on motion of the canal or tragus, otitis externa (also known as swimmer's ear) is a possible diagnosis given the patient's recent swimming history. However, the presence of a bulging and immobile eardrum suggests that the infection is more likely to be in the middle ear.
- B) Bullous otitis: This condition is characterized by the presence of bullae (blisters) on the eardrum, which can be associated with middle ear infections. While it is possible, the description provided does not specifically mention bullae, making acute otitis media a more likely diagnosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- D) Labyrinthitis: Although labyrinthitis (an inner ear infection) is less likely given the presentation, it is a serious condition that can lead to significant complications, including hearing loss and vertigo. The absence of symptoms such as vertigo or nystagmus makes this diagnosis less likely, but it should not be entirely ruled out without further evaluation.
- Rare diagnoses
- C) Foreign body: The history does not suggest the presence of a foreign body in the ear, and the examination does not support this diagnosis.
- F) Otitis media with effusion: This condition is characterized by fluid in the middle ear without signs of acute infection. While it is possible, the patient's symptoms of ear pain and the presence of a red and bulging eardrum suggest an acute infection rather than a chronic condition like otitis media with effusion.