Can Rheumatoid Arthritis (RA) Cause Extensor Tendonitis?

Symptoms of extensor tendonitis include:

• Pain along the length of a tendon
• Pain that gets worse while using the hand or foot
• Stiffness
• Swelling
• Discoloration or warmth around a tendon

Although the exact cause of rheumatoid arthritis (RA) is unknown, researchers speculate that a combination of genetic, hormonal, and environmental factors may play a key role in the development of this condition. Infection, smoking, or physical or emotional stress may also be triggering factors.

• Immune factor
  • RA is an autoimmune disorder that occurs when the immune system attacks the body's tissues and organs.
  • The immune system triggers abnormal inflammation in the synovium (a membrane that lines the joints). When the synovium is inflamed, it causes pain, swelling, and stiffness in the joint.
  • In severe cases, the inflammation affects the bone, cartilage, and other tissues within the joint, causing more serious damage. Abnormal immune reactions underlie the features of RA, affecting other parts of the body.
• Genetics
  • The most significant genetic risk factors for RA are variations in human leukocyte antigen (HLA) genes, especially the HLA-DRB1 gene.
  • The proteins produced from HLA genes help the immune system distinguish the body's proteins from proteins made by foreign invaders (viruses and bacteria). 
• Environmental factors
  • Although the mechanism is unclear, certain factors that may trigger the condition in people at risk include changes in sex hormones (particularly in women), occupational exposure to certain types of dust or fiber, viral, or bacterial infections, and long-term smoking.

Extensor tendonitis is diagnosed as follows:

• Physical examination (the doctor may palpate the hand or foot to check for areas of swelling and tenderness)
• X-rays
• Musculoskeletal ultrasound 
• CT scan
• MRI

Extensor tendonitis is usually treated with a combination of at-home remedies and over-the-counter medications.

• At-home treatment is based on the RICE method
  • Rest: Avoid activities that irritate tendons. 
  • Ice: Apply a cold compress to the hand or foot for 15 minutes; repeat this four times a day.
  • Compression: Wrap the painful area in an elastic bandage to help reduce swelling.
  • Elevation: Prop the hand or foot above the level of the heart as often as possible.
• Over-the-counter medications
  • Nonsteroidal anti-inflammatory drugs
    • Aspirin 
    • Ibuprofen
  • Corticosteroid injections: To decrease inflammation and reduce pain
• Physical therapy: To help regain strength, stability, and movement

In severe cases, affected individuals may develop abnormal inflammation, leading to severe joint damage that limits movement and can cause significant disability.

A few other complications include:

• Osteoporosis
• Rheumatoid nodules (firm bumps of tissue most commonly form around pressure points, such as the elbows)
• Dry eyes and mouth (a disorder characterized by a decrease in the amount of moisture in the eyes and mouth)
• Carpal tunnel syndrome (compression of the nerve due to inflammation)
• Heart problems
• Lung disease
• Lymphoma (a group of blood cancer that develops in the lymph system)