Differential Diagnosis for Knee Pain with Only Touch

• Single most likely diagnosis
  • Prepatellar bursitis: This condition, also known as housemaid's knee, is characterized by inflammation of the bursa in front of the kneecap, which can cause pain when the knee is touched or pressed, especially over the bursa.
• Other Likely diagnoses
  • Patellofemoral pain syndrome: This is a common condition that causes pain around or behind the patella, often related to activities that put stress on the knee, like climbing stairs, and can be exacerbated by touch or pressure.
  • Osgood-Schlatter disease: A condition that affects the upper tibia, causing knee pain, especially in adolescents. It's related to growth spurts and overuse, and the area can be tender to touch.
  • Pes anserine bursitis: Inflammation of the bursa on the lower inside part of the knee, which can cause pain and tenderness to touch in that specific area.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Septic arthritis: Although less common, this is a serious condition where the knee joint becomes infected, leading to severe pain, swelling, and warmth. It requires immediate medical attention and can initially present with pain on touch.
  • Osteonecrosis (avascular necrosis): A condition that occurs when there is loss of blood to the bone, leading to bone death. It can cause knee pain that worsens over time and may be sensitive to touch, especially if it affects the knee joint.
• Rare diagnoses
  • Complex regional pain syndrome (CRPS): A condition characterized by chronic pain, inflammation, and hypersensitivity to touch, following an injury or trauma. It's rare but can affect the knee.
  • Neuroma or nerve entrapment: Abnormal growths of nerve tissue or compression of nerves around the knee can cause pain and sensitivity to touch in specific areas.