Differential Diagnosis for Left Neck Pain with Radiation

Single Most Likely Diagnosis

• Cervical Spondylosis or Cervical Disc Herniation: This condition is the most likely cause due to the radiation of pain from the left ear to the left trapezius and occasional radiation down the left arm, which suggests nerve root impingement. Cervical spondylosis or disc herniation can compress nerves, leading to pain and radiation patterns as described.

Other Likely Diagnoses

• Trapezius Strain or Myofascial Pain Syndrome: Given the involvement of the trapezius muscle, strain or myofascial pain syndrome could be a contributing factor, especially if there's a history of overuse, poor posture, or direct trauma to the area.
• Occipital Neuralgia: This condition involves irritation of the occipital nerves, which can cause pain that radiates from the back of the head to the ear and possibly to the trapezius area, fitting some aspects of the described pain pattern.
• Thoracic Outlet Syndrome (TOS): Although TOS typically presents with symptoms down the arm, some variants can cause pain in the neck and shoulder area, including the trapezius, due to compression of the brachial plexus or subclavian vessels.

Do Not Miss Diagnoses

• Cervical Spine Fracture or Instability: Especially in the context of trauma or in patients with osteoporosis, a fracture or instability in the cervical spine could present with similar pain patterns and is critical to diagnose to prevent further injury.
• Spinal Cord Compression: Conditions like spinal stenosis or a large disc herniation can compress the spinal cord, leading to serious neurological deficits if not promptly addressed.
• Malignancy (e.g., Metastatic Disease to the Cervical Spine): Although less common, cancer can cause neck pain with radiation and should be considered, especially in patients with a history of cancer or those who are older.

Rare Diagnoses

• Temporal Arteritis or Giant Cell Arteritis: While more commonly associated with headache, jaw claudication, and visual symptoms, temporal arteritis could potentially cause referred pain to the neck and trapezius area in some cases.
• Referred Pain from Visceral Sources (e.g., Angina or Esophageal Disease): In rare instances, cardiac or esophageal disease can refer pain to the neck and shoulder area, although this would typically be accompanied by other symptoms like chest pain or dysphagia.