Differential Diagnosis for the Patient's Headache

The patient presented with a headache, and the following differential diagnoses are considered:

• Single most likely diagnosis:
  • Chronic sinusitis: The patient's Head CT impression showed paranasal sinusitis with prominent mucosal thickening in the frontal, right ethmoid, and maxillary sinuses, which is consistent with chronic sinusitis. The patient's symptoms of headache, sinus pressure, and head wound are also consistent with this diagnosis.
• Other Likely diagnoses:
  • Tension headache: The patient's headache could be a tension headache, given the lack of other symptoms such as fever, nausea, or vomiting.
  • Migraine: Although the patient denies sensitivity to light or sound, migraine is still a possible diagnosis, especially given the patient's history of headache.
  • Post-traumatic headache: The patient has a history of a gunshot wound (GSW), which could be contributing to the patient's headache.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Epidural abscess: Although the patient's initial Head CT did not show any acute intracranial abnormality, the subsequent development of an epidural abscess posterior to the frontal sinus highlights the importance of considering this diagnosis, especially in patients with a history of trauma or sinusitis.
  • Meningitis: The patient's symptoms of headache and sinus pressure could be indicative of meningitis, especially if the patient has a history of trauma or immunocompromised state.
  • Subdural hematoma: The patient's history of GSW increases the risk of subdural hematoma, which could present with headache and other neurological symptoms.
• Rare diagnoses:
  • Temporal arteritis: Although the patient is younger than the typical age range for temporal arteritis, it is still a possible diagnosis, especially if the patient has other symptoms such as jaw claudication or visual disturbances.
  • Pituitary apoplexy: The patient's headache and sinus pressure could be indicative of pituitary apoplexy, although this is a rare diagnosis.

Justification for each diagnosis is based on the patient's symptoms, medical history, and the results of the Head CT. The patient's history of GSW and subsequent development of an epidural abscess highlight the importance of considering traumatic and infectious etiologies for the patient's headache.