Differential Diagnosis
- Single most likely diagnosis
- Cluster headache: The patient's symptoms of sharp, pulsating headaches on one side of the head, lasting 20-60 seconds, and recurring every 1-4 minutes are characteristic of cluster headaches. The scalp tenderness and localized pain on the top of the head on the left side also support this diagnosis.
- Other Likely diagnoses
- Tension headache: The patient's symptoms of scalp tenderness and headaches could also be consistent with tension headaches, although the sharp, pulsating nature of the pain is less typical.
- Sinusitis: The patient's history of pneumonia and ongoing fever could suggest a secondary infection such as sinusitis, which could cause headaches.
- Medication overuse headache: The patient has been taking antibiotics for 2 days, but if they were taking other medications such as pain relievers, they could be at risk for medication overuse headache.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Subarachnoid hemorrhage: Although the patient's symptoms are not typical of a subarachnoid hemorrhage, any new onset of severe headache warrants consideration of this diagnosis.
- Meningitis: The patient's fever and headache could suggest meningitis, especially if they have a compromised immune system or other risk factors.
- Temporal arteritis: The patient's age is not specified, but if they are over 50, temporal arteritis should be considered, especially with symptoms of scalp tenderness and headaches.
- Rare diagnoses
- Trigeminal neuralgia: The patient's sharp, pulsating pain could be consistent with trigeminal neuralgia, although this is a less common condition.
- Occipital neuralgia: The patient's symptoms of scalp tenderness and headaches could also be consistent with occipital neuralgia, although this is a less common condition.
- Cervicogenic headache: The patient's headaches could be referred from the cervical spine, although this is a less common condition.