What is pannus?

Rheumatoid arthritis (RA) is an autoimmune disease that causes your body’s immune system to attack your joints. This causes swelling, pain, and pannus — an abnormal tissue growth in the joints.

This tissue can spread to your bones and cartilage, causing cartilage destruction, bone deterioration, pain, and inflammation.

Though this disorder can affect any joint in the body, the joints that are classically affected in rheumatoid arthritis are the joints of the hands and fingers.

Rheumatoid pannus formation

When RA attacks your joints, it also attacks the surrounding tissues. The tissue that lines your joints is the synovial membrane or the synovium. The normal synovium that lubricates your joints is only a few blood cells thick.

When you develop RA, your white blood cells attack the synovium, releasing proteins that cause blood vessels in the synovium to multiply. This increased blood flow encourages tissue growth at an unhealthy rate.

In response, your synovial membrane will thicken and take over the small space between your joints and bones. The pannus can become rough and irregular and will eventually cover your bones and cartilage.

Pannus can also grow in the hands, eye cornea, prosthetic heart valve, and abdomen. Over time, it can resemble a tumor.

Pannus side effects

Pannus growth can cause bone and cartilage damage over time. Without proper treatment, it can cause:

  • pain
  • irreversible damage to your tendons
  • damage to bone marrow
  • bone deterioration
  • permanent deformity

Pannus can also cause excess fluid production.

Your synovial membrane produces small amounts of fluid to keep your joints lubricated. If pannus grows, it also produces more fluid. This can cause inflammation, joint swelling, and tissue deterioration.

Treatment options

Treatment for RA depends on the severity of your condition. Nonsteroidal anti-inflammatory drugs (NSAIDs) are common treatment options that help to reduce pain and inflammation. NSAIDs are available as a pill or a skin patch.

Doctors may prescribe corticosteroid medication to decrease inflammation and help slow pannus growth. Some common corticosteroid drugs used for RA include:

Your doctor will only recommend these drugs short term. Though effective, corticosteroids can cause a number of side effects over time, including:

More definitive treatment for RA consists of disease-modifying anti-rheumatic drugs (DMARDs) and targeted biologic agents. These medications are being prescribed earlier in the treatment of RA in an effort to prevent joint destruction.

DMARDs are used to block inflammation and prevent further joint damage. There are many different types of DMARDs, and they all work differently.

Hydroxychloroquine, available as an oral supplement, is a DMARD used to treat malaria, lupus, and RA. It reduces swelling from this condition and may also help prevent joint damage.

Researchers are still trying to understand why it’s effective, but it’s believed hydroxychloroquine helps decrease chemical production in the immune response.

Methotrexate is another DMARD and one of the oldest. Once in the system, this drug converts to methotrexate polyglutamate to reduce swelling and inflammation.

Other DMARDs are:

Another class of DMARDs are biologics. Biologics used to treat RA include:

In more serious cases, your doctor may recommend surgery to replace the affected joints. This restores mobility and relieves pain. In this procedure, your doctor replaces your damaged joints with metal and plastic parts.

What’s the outlook?

Rheumatoid arthritis causes joint pain because of inflammation and the growth of pannus. This leads to cartilage destruction, bone deterioration, loss of joint function, and loss of mobility.

Treatment options include anti-inflammatory medications, disease-modifying medications, targeted treatment with biologics, and surgical options.

You can also take an active role in your treatment with some self-care practices. Maintaining a diet rich in antioxidants can reduce joint inflammation. Proper rest can also protect your joints from overuse.

If you begin to experience any discomfort within your joints, call your doctor to get an accurate diagnosis and discuss treatment options.