Differential Diagnosis for the Patient's Condition

The patient presents with pain on the left side of the head above the earlobe, which initially responded to analgesic injection but recurred. The pain is continuous for the last 36 hours and is not relieved by analgesics. The patient also has a history of lower back injury on the left side and experiences pain when getting up from a sitting position. Blood pressure is currently normal.

• Single Most Likely Diagnosis
  • Temporomandibular Joint (TMJ) Disorder: The location of the pain above the earlobe and the initial response to analgesics suggest a musculoskeletal origin. TMJ disorders can cause pain in this area, especially if there's a history of trauma or strain, which could be related to the lower back injury and altered posture or movement patterns.
• Other Likely Diagnoses
  • Tension Headache: Given the description of the pain and its initial relief with analgesics, tension headache is a possibility. However, the specific location and the relation to the lower back injury might make this less likely.
  • Cervicogenic Headache: Pain referred from the cervical spine can present in the head, including above the ear. The history of lower back injury and pain upon standing could indicate a broader musculoskeletal issue affecting the cervical spine.
  • Dental Issues: Toothache or dental problems can refer pain to the side of the head. Although not directly mentioned, it's a common cause of unilateral head pain.
• Do Not Miss Diagnoses
  • Temporal Arteritis: Although less common in a 30-year-old, temporal arteritis can cause severe, unilateral head pain and is a medical emergency due to the risk of vision loss. The absence of other typical symptoms (e.g., jaw claudication, visual disturbances) does not rule it out entirely.
  • Meningitis or Subarachnoid Hemorrhage: These are severe conditions that can present with sudden, severe headache. While the patient's presentation does not strongly suggest these, they are critical to consider due to their potential for severe outcomes.
• Rare Diagnoses
  • Trigeminal Neuralgia: This condition causes intense pain along a branch of the trigeminal nerve, which could potentially present above the earlobe. However, the pain is typically more severe and shock-like.
  • Occipital Neuralgia: Involves the nerves that run from the base of the skull to the scalp and can cause pain on one side of the head. It's less common and might not fully explain the patient's symptoms without further investigation.

Each diagnosis is considered based on the patient's symptoms, history, and the need to rule out potentially dangerous conditions. A thorough examination, including neurological and musculoskeletal assessments, and possibly imaging studies, would be necessary to determine the exact cause of the patient's pain.