Differential Diagnosis for Knee Swelling
- Single most likely diagnosis
- Prepatellar Bursitis: This condition is likely given the patient's history of frequent kneeling, which can cause irritation and inflammation of the prepatellar bursa. The presence of a lump on the bottom of the kneecap, which filled back up after attempted drainage, and the associated redness, swelling, and warmth, are consistent with this diagnosis.
- Other Likely diagnoses
- Septic Bursitis: The patient's attempt to drain the area and the presence of blood and fluid, along with the worsening symptoms of redness, swelling, and warmth, could indicate a septic bursitis, which is an infection of the bursa.
- Hemorrhagic Bursitis: The presence of blood after attempted drainage could also suggest a hemorrhagic bursitis, which is a collection of blood in the bursa.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Deep Vein Thrombosis (DVT): Although less likely, the patient's symptoms of redness and swelling extending down to the foot could be indicative of a DVT, which is a blood clot in the deep veins of the leg. This condition can be life-threatening if not promptly diagnosed and treated.
- Cellulitis: The patient's symptoms of redness, swelling, and warmth could also indicate cellulitis, a bacterial skin infection that can spread rapidly and become severe if not treated promptly.
- Rare diagnoses
- Synovial Chondromatosis: This is a rare condition characterized by the growth of cartilage in the synovial membrane of the joint, which can cause swelling and a lump. However, it is less likely given the patient's symptoms and history.
- Gout or Pseudogout: These conditions are characterized by sudden, severe joint pain and swelling, but are less likely given the patient's symptoms and history of frequent kneeling.