Differential Diagnosis
The patient's presentation of shakiness, palpitations, and headaches while recovering from agranulocytosis and a retropharyngeal abscess, and being treated with daptomycin, piperacillin/tazobactam, with a negative CT of the head, suggests a complex clinical picture. Here's a categorized differential diagnosis:
Single Most Likely Diagnosis
- Medication side effects: The patient is on multiple medications (daptomycin, piperacillin/tazobactam), which can cause side effects such as shakiness (tremors), palpitations, and headaches. Daptomycin, for example, can cause muscle weakness and tremors, while piperacillin/tazobactam can lead to neurological effects, though less commonly.
Other Likely Diagnoses
- Sepsis or systemic infection: Despite the negative CT head and treatment for the retropharyngeal abscess, the patient could still be experiencing systemic effects of infection, including shakiness and palpitations due to cytokine release and potential cardiac effects.
- Electrolyte imbalance: Patients recovering from severe infections and on broad-spectrum antibiotics are at risk for electrolyte imbalances (e.g., hypokalemia, hypomagnesemia), which can cause muscle weakness, tremors, palpitations, and headaches.
- Anemia or other hematologic effects: Given the patient's history of agranulocytosis, there could be other hematologic abnormalities, such as anemia, which might contribute to symptoms like palpitations and headaches.
Do Not Miss Diagnoses
- Endocarditis: Although less likely, given the patient's recent infection and the use of antibiotics, endocarditis could explain the palpitations and potentially the headaches if there were embolic phenomena.
- CNS vasculitis or cerebral venous sinus thrombosis: These conditions are rare but could present with headaches and, in the case of vasculitis, possibly systemic symptoms like shakiness. The negative CT head makes these less likely but not impossible, especially if the study was not comprehensive or if the conditions are early in their course.
- Adrenal insufficiency: This could be a consequence of prolonged stress from infection and would explain a range of symptoms including shakiness, palpitations, and potentially headaches.
Rare Diagnoses
- Neurosyphilis: If the patient has untreated syphilis, neurosyphilis could present with a wide range of neurological symptoms, including tremors and headaches.
- Wilson's disease: A genetic disorder leading to copper accumulation, which can cause tremors, among other neurological symptoms. However, this would be extremely rare in an 88-year-old without a prior diagnosis.
- Pheochromocytoma: A rare tumor of the adrenal gland that could cause episodic palpitations, headaches, and tremors due to catecholamine release.