Differential Diagnosis for Decreased Sense of Smell
- Single most likely diagnosis
- Post-traumatic olfactory dysfunction: The patient has a history of a canal being removed years ago, which could have damaged the olfactory nerves, leading to a decreased sense of smell.
- Other Likely diagnoses
- Viral upper respiratory infection: The patient's symptoms started in November, which is a common time for upper respiratory infections, and the decreased sense of smell could be a lingering effect.
- Chronic rhinosinusitis: Although the sinuses appear clear on the imaging, chronic rhinosinusitis can cause a decrease in the sense of smell, and the patient may not have been experiencing active symptoms at the time of the scan.
- Nasal polyposis: The imaging does not show any evidence of nasal polyposis, but it is possible that the patient has a small polyp or other nasal obstruction that is not visible on the scan.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningioma: Although the imaging does not show any evidence of a tumor, a meningioma in the anterior cranial fossa could cause a decrease in the sense of smell, and it is essential to consider this possibility to avoid missing a potentially life-threatening diagnosis.
- Esthesioneuroblastoma: This is a rare tumor that originates in the olfactory nerves and can cause a decrease in the sense of smell, and it is crucial to consider this possibility to avoid missing a potentially life-threatening diagnosis.
- Rare diagnoses
- Kallmann syndrome: This is a rare genetic disorder that affects the development of the olfactory nerves and can cause a decrease in the sense of smell, but it is typically diagnosed in childhood or adolescence.
- Traumatic injury to the olfactory nerves: Although the patient has a history of a canal being removed, it is possible that the patient experienced a traumatic injury to the olfactory nerves that is not related to the previous surgery.