Differential Diagnosis for the Patient's Symptoms
The patient presents with a 2-week history of an increasingly severe tremor in her hands, which has been exacerbated by recent medication changes. Here is a categorized differential diagnosis:
- Single most likely diagnosis
- E) Lithium toxicity: The patient has been taking lithium carbonate for 12 years and recently started oxaprozin, which can increase lithium levels by decreasing its renal clearance. The coarse tremor is a classic symptom of lithium toxicity, making this the most likely explanation for her symptoms.
- Other Likely diagnoses
- A) Citalopram toxicity: Although less likely, citalopram can cause tremors, especially at high doses or in combination with other medications. However, the patient's symptoms and medication history make lithium toxicity more probable.
- D) Essential tremor: This is a common movement disorder that could be exacerbated by stress, anxiety, or certain medications. However, the acute onset and severity of the tremor in this case make it less likely.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- B) Complex partial seizure disorder: Although rare, a complex partial seizure disorder could present with tremors or other motor symptoms. It is essential to consider this diagnosis to avoid missing a potentially life-threatening condition.
- F) Oxaprozin toxicity: While oxaprozin is not typically associated with tremors, it can cause other adverse effects, such as gastrointestinal bleeding or renal impairment. It is crucial to monitor the patient's renal function and adjust medications accordingly.
- Rare diagnoses
- C) Conversion disorder: This is a psychological condition that can present with motor symptoms, including tremors. However, the patient's reactive affect and lack of other psychological symptoms make this diagnosis less likely.
- Other rare diagnoses, such as Wilson's disease or thyroid disorders, could also be considered, but they are less likely given the patient's presentation and medication history.