Differential Diagnosis for a 13-year-old Female with Left Knee Arthritis
Single Most Likely Diagnosis
- Juvenile Idiopathic Arthritis (JIA): This is the most common cause of arthritis in children and adolescents, characterized by chronic joint inflammation. The presentation of a warm, red, and swollen knee in a 13-year-old female is consistent with oligoarticular JIA, which often affects large joints like the knee.
Other Likely Diagnoses
- Septic Arthritis: Bacterial infection within the joint space, which can cause rapid onset of pain, swelling, redness, and warmth. It's a common concern in pediatric patients presenting with acute monoarthritis.
- Traumatic Synovitis: Inflammation of the synovial membrane due to trauma, which can lead to symptoms similar to those described.
- Osgood-Schlatter Disease: A condition causing knee pain in adolescents due to inflammation of the patellar tendon at its insertion on the tibia, though it typically doesn't cause the knee to be warm and red.
Do Not Miss Diagnoses
- Lyme Arthritis: Caused by Borrelia burgdorferi, it can present with intermittent episodes of arthritis, particularly in the knee. Missing this diagnosis could lead to prolonged morbidity.
- Gonococcal Arthritis: A sexually transmitted infection that can cause septic arthritis, especially in adolescents. It's crucial to consider this in the differential due to its potential for serious complications if untreated.
- Tuberculous Arthritis: Although rare, tuberculosis can affect joints and has a varied presentation, making it a "do not miss" diagnosis due to its potential severity and the need for specific treatment.
Rare Diagnoses
- Rheumatic Fever: An autoimmune complication of streptococcal infection, which can cause migratory polyarthritis, though it's less common in the presentation of a single, swollen joint.
- Hemophilic Arthropathy: In patients with hemophilia, recurrent joint bleeds can lead to chronic arthritis. This would be considered in patients with a known history of hemophilia.
- Sarcoid Arthritis: A rare condition where sarcoidosis affects the joints, causing arthritis. It's less common in children and adolescents but should be considered in the differential diagnosis of chronic arthritis.