Differential Diagnosis for Patient with Persistent Headache
Single Most Likely Diagnosis
- Tension headache or stress-related headache: The patient's headache is relieved by paracetamol, which is commonly used for tension headaches. The stress of hospitalization and the initial illness could contribute to this type of headache.
Other Likely Diagnoses
- Post-infectious headache: Given the patient's recent infection (acute pyelonephritis), it's possible that the headache is a post-infectious complication, which can occur even after the resolution of the primary infection.
- Dehydration headache: Despite the resolution of fever and flank pain, dehydration could still be a factor, especially if the patient's fluid intake has not been adequate, leading to a headache.
- Medication-overuse headache: If the patient has been taking paracetamol frequently for pain management, there's a possibility of developing a medication-overuse headache, although this typically requires more frequent and longer-term use.
Do Not Miss Diagnoses
- Subarachnoid hemorrhage or other intracranial hemorrhage: Although the plain cranial CT scan was negative, it's crucial not to miss a potentially life-threatening condition like a subarachnoid hemorrhage, especially if the headache was sudden and severe at onset. A lumbar puncture might be considered if clinical suspicion remains high.
- Meningitis: Given the patient's recent infection, meningitis could be a consideration, especially if there are other symptoms such as neck stiffness or altered mental status, despite the negative CT scan.
- Cerebral venous sinus thrombosis: This condition can present with headache and is a known complication of dehydration, infection, and possibly the use of certain medications.
Rare Diagnoses
- Headache due to a cerebral vasculitis: This is a rare condition that could be associated with systemic infections or autoimmune disorders, presenting with headache among other symptoms.
- Pituitary apoplexy: A rare condition that involves sudden hemorrhage or infarction of the pituitary gland, which can present with a severe headache, although typically accompanied by other specific symptoms like visual disturbances or acute endocrine deficiencies.