Differential Diagnosis for Sudden and Severe Joint Pain
Single Most Likely Diagnosis
- Gout: This condition is characterized by sudden, severe attacks of pain, swelling, redness, and tenderness in one or more joints, often occurring overnight. The knees and elbows are common sites for gout attacks, which can be triggered by various factors including diet, alcohol consumption, and certain medications.
Other Likely Diagnoses
- Pseudogout (Calcium Pyrophosphate Deposition Disease, CPPD): Similar to gout, pseudogout causes sudden, severe joint pain and swelling, but it is due to the deposition of calcium pyrophosphate dihydrate crystals within the joint. The knees are the most commonly affected joint.
- Septic Arthritis: This is an infection within a joint, which can cause sudden and severe pain, swelling, and reduced mobility. It's a medical emergency that requires prompt treatment to prevent joint destruction.
- Rheumatoid Arthritis (RA) Flare: While RA typically has a more gradual onset, a flare can cause sudden worsening of symptoms, including severe joint pain and swelling in multiple joints, such as the knees and elbows.
Do Not Miss Diagnoses
- Septic Arthritis (repeated for emphasis): Due to its potential for rapid joint destruction and systemic infection, it's crucial not to miss this diagnosis.
- Lyme Arthritis: Caused by the bacterium Borrelia burgdorferi, Lyme disease can lead to sudden onset of joint pain and swelling, particularly in the knees. Early diagnosis and treatment are essential to prevent long-term complications.
Rare Diagnoses
- Seronegative Spondyloarthropathies (e.g., Psoriatic Arthritis, Reactive Arthritis): These conditions can cause sudden joint pain and inflammation but are less common and often associated with other systemic symptoms or skin findings.
- Hemochromatosis: A genetic disorder leading to iron overload, which can cause joint pain and arthritis, among other symptoms. It's less likely to present with sudden severe joint pain but should be considered in the differential due to its potential for significant morbidity if untreated.
- Sarcoid Arthritis: A condition where sarcoidosis, an inflammatory disease, affects the joints, leading to pain and swelling. It's rare and often associated with other systemic manifestations of sarcoidosis.