Differential Diagnosis for Sudden Onset of Discoloration of Toe in a Diabetic Patient

• Single most likely diagnosis:
  • Diabetic foot ulcer with ischemia or infection: This is a common complication in diabetic patients due to neuropathy and peripheral arterial disease, leading to decreased sensation and poor circulation, which can result in unnoticed trauma and subsequent infection or ischemia.
• Other Likely diagnoses:
  • Trauma: Even minor trauma can lead to significant complications in diabetic patients due to impaired healing and increased risk of infection.
  • Chilblains: A condition caused by prolonged exposure to cold, leading to inflammation of small blood vessels, which can cause discoloration and pain.
  • Raynaud's phenomenon: Although less common, this condition can cause vasospasm of the arteries supplying blood to the toes, leading to discoloration.
• Do Not Miss diagnoses:
  • Dry gangrene: A serious condition resulting from ischemia, which can lead to tissue death if not promptly addressed.
  • Wet gangrene: A severe infection that can spread rapidly and is life-threatening if not treated immediately.
  • Embolic event: An acute blockage of an artery supplying the toe, which is a medical emergency.
  • Sepsis: A systemic infection that can arise from a localized infection in the toe, which is life-threatening and requires immediate intervention.
• Rare diagnoses:
  • Buerger's disease (Thromboangiitis obliterans): A rare disease of the arteries and veins in the arms and legs, which can lead to ischemia and tissue damage.
  • Erythromelalgia: A disorder characterized by burning pain, heat, and redness in the hands and feet, which can sometimes present with discoloration.
  • Complex regional pain syndrome (CRPS): A condition characterized by chronic pain, inflammation, and hypersensitivity, which can occasionally present with changes in skin color and temperature.