Differential Diagnosis for Intermittent Knee Swelling
Single Most Likely Diagnosis
- Meniscal Tear: This is a common cause of intermittent knee swelling, especially if the swelling is associated with activities that involve twisting or bending of the knee. Meniscal tears can lead to the accumulation of fluid within the knee joint, resulting in swelling.
Other Likely Diagnoses
- Ligament Sprain: Sprains of the knee ligaments, such as the anterior cruciate ligament (ACL) or medial collateral ligament (MCL), can cause intermittent swelling due to inflammation and fluid accumulation.
- Osteoarthritis: Early stages of osteoarthritis can present with intermittent knee swelling, especially after activity. The swelling is due to the inflammatory response and joint fluid accumulation.
- Patellofemoral Pain Syndrome: This condition, characterized by pain around or behind the patella, can also lead to intermittent swelling, particularly after activities that put stress on the knee, like climbing stairs or squatting.
Do Not Miss Diagnoses
- Septic Arthritis: Although less common, septic arthritis is a medical emergency that requires prompt diagnosis and treatment. It presents with sudden onset of pain, swelling, and decreased range of motion, often accompanied by systemic symptoms like fever.
- Tumor (e.g., Synovial Sarcoma): Though rare, tumors around the knee can cause intermittent swelling. It's crucial to consider this diagnosis to avoid delayed treatment.
- Deep Vein Thrombosis (DVT): DVT can cause swelling in the leg, including around the knee. It's a critical diagnosis to consider due to the risk of pulmonary embolism.
Rare Diagnoses
- Hemophilia: In patients with hemophilia, even minor trauma can lead to significant bleeding into the joint (hemarthrosis), causing swelling.
- Pigmented Villonodular Synovitis (PVNS): A rare condition characterized by the proliferation of synovial tissue, leading to chronic swelling and potentially causing bone erosion.
- Knee Effusion due to Systemic Diseases (e.g., Rheumatoid Arthritis, Lupus): While these conditions are not rare, their presentation with isolated intermittent knee swelling might be less common. However, they are important to consider in the differential diagnosis due to their potential for significant morbidity if not treated appropriately.