Differential Diagnosis for the 60-year-old Male with Pain and Bluish Discoloration of the Left Upper Limb
- Single most likely diagnosis:
- Acute arterial embolism or thrombosis: This is likely due to the sudden onset of pain and bluish discoloration (cyanosis) in the left upper limb, despite normal pulses in the more proximal arteries (radial, brachial, and axillary). The inability of the pulse oximeter to read saturation in the left upper limb suggests impaired blood flow to the limb.
- Other Likely diagnoses:
- Vasospastic disorder (e.g., Raynaud's phenomenon): This could explain the bluish discoloration and pain, especially if triggered by cold or stress. However, the acute onset and the fact that pulse oximetry cannot obtain a reading might suggest a more severe obstruction.
- Thoracic outlet syndrome: This condition involves compression of the nerves and/or blood vessels that pass into the thoracic outlet (the space between your collarbone and first rib). It could lead to pain and decreased blood flow to the arm, but typically does not cause such an acute presentation with cyanosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Aortic dissection: Although the 2D echo is normal, a type B aortic dissection could potentially involve the subclavian artery, leading to decreased blood flow to the left arm. This is a life-threatening condition that requires immediate diagnosis and treatment.
- Pulmonary embolism with paradoxical embolism: If there's a patent foramen ovale, a pulmonary embolism could lead to a paradoxical embolism, where the clot crosses from the right to the left side of the heart and then lodges in a peripheral artery, such as the subclavian artery.
- Rare diagnoses:
- Buerger's disease (Thromboangiitis obliterans): A rare disease of the arteries and veins in the arms and legs, which can lead to blockages and reduced blood flow, resulting in pain, cyanosis, and potentially gangrene.
- Arteritis (e.g., giant cell arteritis or Takayasu arteritis): These are inflammatory conditions that can affect the arteries and lead to decreased blood flow to the limbs. They are less common and might present with additional systemic symptoms.