Differential Diagnosis

The patient's presentation of neck pain, particularly on the right back side, with deep and sore sensation, warrants a thorough evaluation of potential causes. Here's a categorized differential diagnosis:

• Single most likely diagnosis
  • Muscle Strain: Given the patient's symptoms of soreness, alleviation with NSAIDs and muscle relaxants, and the absence of sharp pains or fever, a muscle strain is the most plausible explanation. The fact that the pain is constant and not relieved by position change also supports this diagnosis.
• Other Likely diagnoses
  • Cervical Facet Joint Pain: This condition can cause deep, aching pain in the neck, often unilateral, and may be exacerbated by certain movements or positions. The patient's description of deep pain could align with facet joint involvement.
  • Tension Myalgia: Although the patient mentions that changing positions does not help, tension myalgia (muscle pain due to tension) could still be a consideration, especially if the pain is related to stress or poor posture.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Cervical Spine Fracture: Although less likely without a history of trauma, it's crucial to consider the possibility of a fracture, especially if the pain is severe and unrelenting. A fracture could lead to serious complications, including spinal cord injury.
  • Meningitis: While the patient does not have fever or headache, which are common symptoms of meningitis, the deep neck pain could potentially be a presenting symptom of this serious infection, especially if it involves the cervical spine.
  • Cervical Disc Herniation: A herniated disc could cause deep, severe pain, especially if it compresses a nerve root. This condition might not always present with the typical radiating pain down the arm but could cause significant neck pain.
• Rare diagnoses
  • Cervical Spinal Stenosis: This condition involves narrowing of the spinal canal and could cause neck pain, but it's more common in older adults and typically presents with symptoms of neurogenic claudication or radiculopathy.
  • Neck Tumors: Although extremely rare, tumors in the neck region could cause deep, persistent pain. The absence of other symptoms like weight loss or night pain makes this less likely, but it remains a consideration in a thorough differential diagnosis.

Each of these diagnoses should be considered in the context of the patient's full medical history, physical examination, and potentially, diagnostic imaging or other tests to determine the underlying cause of the neck pain.