What is the differential diagnosis for a 19-year-old patient presenting with numbness and swelling of the right lower extremity (RLE), knee pain, and color change of the RLE after a sunburn?

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Differential Diagnosis for 19-year-old with Numbness and Swelling of RLE, Knee Pain, and Color Change after Sunburn

  • Single Most Likely Diagnosis
    • Complex Regional Pain Syndrome (CRPS): This condition is characterized by numbness, swelling, and color changes in the affected limb, often triggered by an injury or trauma, such as a sunburn. The symptoms described, including the specific mention of changes after a sunburn, align closely with CRPS.
  • Other Likely Diagnoses
    • Cellulitis: An infection of the skin and subcutaneous tissues that could cause swelling, pain, and color changes. The recent sunburn could have compromised the skin's integrity, making it susceptible to infection.
    • Deep Vein Thrombosis (DVT): Although less common in young individuals, DVT could cause swelling, pain, and color changes in the leg. The recent sunburn might not be directly related but could be a coincidental finding.
    • Peripheral Artery Disease (PAD): Though uncommon in a 19-year-old, PAD could lead to pain and color changes, especially if there's a significant reduction in blood flow to the limb.
  • Do Not Miss Diagnoses
    • Compartment Syndrome: A medical emergency that could present with pain, swelling, and numbness, especially after an injury. The knee pain and swelling could indicate increased pressure within the muscle compartments of the leg.
    • Pulmonary Embolism (if DVT is suspected): If there's a concern for DVT, it's crucial to consider the possibility of a pulmonary embolism, which is a life-threatening condition.
    • Sepsis (if infection is suspected): In cases where an infection like cellulitis is considered, it's essential to rule out sepsis, a potentially fatal condition resulting from an overwhelming infection.
  • Rare Diagnoses
    • Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet, which could potentially be triggered by a sunburn.
    • Raynaud’s Phenomenon: A condition that affects blood flow to the fingers and toes, and sometimes the ears, nose, and lips, causing them to turn blue or white in response to cold or stress. While less common in the legs, it could be considered in the differential for color changes.
    • Neurological conditions such as peripheral neuropathy or nerve entrapment syndromes could also present with numbness and pain but would be less likely given the acute onset and specific triggers mentioned.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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