Differential Diagnosis for Erosive Arthritic Changes with Synovitis Involving Small Joints
Single Most Likely Diagnosis
- Rheumatoid Arthritis (RA): This is the most common cause of erosive arthritic changes with synovitis involving small joints. RA is a chronic autoimmune disorder characterized by symmetric polyarthritis, often affecting the hands and feet, with morning stiffness, and can lead to significant disability if not treated promptly.
Other Likely Diagnoses
- Psoriatic Arthritis (PsA): This condition combines the swollen, scaly skin of psoriasis with joint pain and arthritis. It can cause erosive changes and synovitis, particularly in the small joints of the hands and feet, and is often asymmetric.
- Osteoarthritis (OA) with Erosive Changes: While OA is typically non-erosive, an erosive subset can mimic the presentation of other arthritic conditions, especially in the small joints of the hands.
- Lupus Arthritis: Systemic Lupus Erythematosus (SLE) can cause an inflammatory arthritis that may involve small joints and can be erosive, though this is less common.
Do Not Miss Diagnoses
- Septic Arthritis: Although less likely, septic arthritis is a medical emergency that requires immediate attention. It can present with sudden onset of pain, swelling, and decreased range of motion in a single joint, and can rapidly progress to joint destruction if not treated.
- Crystal Arthropathies (Gout or Pseudogout): These conditions can cause acute, severe joint pain and swelling, and while they are more commonly associated with larger joints, they can involve small joints and cause erosive changes over time.
- Lyme Arthritis: Caused by the bacterium Borrelia burgdorferi, Lyme disease can lead to arthritis, particularly in the knee, but can also affect small joints. It's crucial to consider this diagnosis, especially in endemic areas.
Rare Diagnoses
- Sjögren's Syndrome: An autoimmune disorder that can cause arthritis, particularly affecting small joints, along with dry eyes and dry mouth.
- Reactive Arthritis: Previously known as Reiter's syndrome, this form of arthritis occurs as a reaction to an infection elsewhere in the body, often in the gastrointestinal tract or the urethra.
- Hemochromatosis: A genetic disorder that leads to iron overload, which can cause arthropathy, particularly affecting the small joints of the hands, similar to OA.
- Whipple's Disease: A rare, systemic bacterial infection that can cause arthritis among other symptoms, though joint involvement is less common.