Differential Diagnosis for Joint Pain without Positive ANA and RF

• Single Most Likely Diagnosis
  • Osteoarthritis: This is the most common cause of joint pain in adults, characterized by wear and tear of the joint cartilage. The absence of positive ANA (Antinuclear Antibody) and RF (Rheumatoid Factor) makes autoimmune causes less likely, pointing towards a more mechanical or degenerative condition like osteoarthritis.
• Other Likely Diagnoses
  • Gout: A form of inflammatory arthritis characterized by sudden, severe attacks of pain, swelling, redness, and tenderness in one or more joints, most often in the big toe. It is not typically associated with positive ANA or RF.
  • Pseudogout (Calcium Pyrophosphate Deposition Disease, CPPD): Similar to gout but caused by calcium pyrophosphate dihydrate crystal deposition within the joint. It also does not typically present with positive ANA or RF.
  • Traumatic or Overuse Injuries: Conditions such as tendinitis, bursitis, or ligament sprains can cause joint pain without any autoimmune markers being positive.
• Do Not Miss Diagnoses
  • Septic Arthritis: Although less common, this condition is a medical emergency. It is an infection within a joint, which can rapidly lead to destruction of the joint if not promptly treated. The absence of positive ANA and RF does not rule out septic arthritis.
  • Lyme Arthritis: Caused by the bacterium Borrelia burgdorferi, transmitted to humans through the bite of infected black-legged ticks. It can cause joint pain and swelling, particularly in the knee, without positive autoimmune markers.
  • Hemochromatosis: A genetic disorder characterized by excessive iron accumulation in the body, leading to joint pain among other symptoms. It's crucial to diagnose as it can lead to severe organ damage if untreated.
• Rare Diagnoses
  • Hemophilic Arthropathy: In patients with hemophilia, recurrent bleeding into joints can lead to chronic joint pain and degeneration.
  • Charcot Joint (Neuropathic Arthropathy): A condition characterized by progressive degeneration of a weight-bearing joint, often due to a neurological condition that impairs sensation, leading to repetitive trauma and joint destruction without the patient realizing it.
  • Sarcoid Arthritis: A condition where sarcoidosis, an inflammatory disease, affects the joints, causing pain and swelling. It is less common and might not always present with typical autoimmune markers.