Differential Diagnosis for a 45-year-old Woman with Swelling on Left Leg, Fever, and Purple Discoloration Rash/Necrosis
- Single most likely diagnosis:
- Deep Vein Thrombosis (DVT) with phlegmasia cerulea dolens: This condition is characterized by a sudden onset of swelling, pain, and discoloration of the affected limb due to a blood clot in the deep veins. The presence of fever and purple discoloration (phlegmasia cerulea dolens) suggests a severe form of DVT that can lead to necrosis if not promptly treated.
- Other Likely diagnoses:
- Cellulitis with necrotizing fasciitis: This is a bacterial infection of the skin and soft tissues that can cause swelling, redness, and necrosis. The absence of itching and the presence of fever and necrosis suggest a severe infection.
- Septic thrombophlebitis: This condition involves a blood clot in a vein that becomes infected, leading to symptoms such as swelling, fever, and discoloration.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Necrotizing fasciitis: Although mentioned earlier, it's crucial to reiterate the importance of considering this diagnosis due to its high mortality rate if not promptly recognized and treated.
- Gas gangrene: This is a rare but life-threatening condition caused by a bacterial infection that produces gas in the tissues, leading to necrosis and potentially fatal outcomes.
- Severe sepsis or septic shock: The presence of fever, swelling, and necrosis could indicate a systemic infection that has progressed to sepsis or septic shock, conditions that require immediate medical attention.
- Rare diagnoses:
- Purpura fulminans: This is a rare condition characterized by the sudden onset of hemorrhagic necrosis of the skin, often associated with severe infections or genetic disorders.
- Antiphospholipid syndrome: This autoimmune disorder can cause blood clots, including those in the deep veins, and is associated with a variety of symptoms including skin manifestations.
- Vasculitis (e.g., polyarteritis nodosa): These are inflammatory conditions that affect the blood vessels and can cause a range of symptoms including skin lesions and necrosis.