Differential Diagnosis for a 25-year-old Patient with Numbness, Tingling, and Pain

The patient's presentation of numbness and tingling in the left pinkie finger and ring finger, along with pain in the left arm and shoulder region, suggests a possible ulnar nerve involvement. However, the accompanying chest pain that worsens with breathing and arm movement complicates the diagnosis, requiring a broader differential.

• Single Most Likely Diagnosis
  • Ulnar Nerve Entrapment or Compression: The distribution of numbness and tingling specifically in the pinkie and ring fingers is highly suggestive of ulnar nerve involvement. Symptoms worsening with certain positions or activities like holding a phone support this diagnosis, as these actions can exacerbate nerve compression.
• Other Likely Diagnoses
  • Thoracic Outlet Syndrome (TOS): Given the pain in the shoulder and chest area that worsens with arm movement and breathing, TOS is a plausible diagnosis. TOS can involve compression of the nerves (including the ulnar nerve) and/or blood vessels that pass through the thoracic outlet.
  • Cervical Radiculopathy: The symptoms of pain in the arm and shoulder, along with numbness in specific fingers, could also indicate a cervical radiculopathy, particularly if the nerve root involved is C8, which affects the ulnar nerve distribution.
• Do Not Miss Diagnoses
  • Pulmonary Embolism: Although less likely given the chronic nature of symptoms, any chest pain that worsens with breathing (pleuritic chest pain) must prompt consideration of pulmonary embolism, a potentially life-threatening condition.
  • Acute Coronary Syndrome: While rare in a 25-year-old, any chest pain, especially if associated with exertion or movement, necessitates ruling out cardiac causes, including acute coronary syndrome.
  • Spinal Cord Compression or Injury: Symptoms of numbness, tingling, and pain, especially if worsening or accompanied by other neurological deficits, could indicate spinal cord compression or injury, requiring urgent evaluation.
• Rare Diagnoses
  • Pancoast Tumor: A rare type of lung cancer that can cause shoulder and arm pain, along with numbness and tingling, due to invasion of the brachial plexus.
  • Multiple Sclerosis: An autoimmune disease that can cause a wide range of neurological symptoms, including numbness and tingling, though the specific distribution and accompanying chest pain would be unusual for MS.
  • Brachial Plexitis (Neuralgic Amyotrophy): An inflammatory condition of the brachial plexus that can cause severe pain in the shoulder and arm, followed by weakness and numbness, though it typically presents with more widespread arm involvement.

Each of these diagnoses requires careful consideration of the patient's history, physical examination, and potentially, further diagnostic testing to determine the underlying cause of their symptoms.