Rheumatoid arthritis

• Rheumatoid arthritis is an autoimmune disorder that causes chronic inflammation of the joints.
• The exact trigger for rheumatoid arthritis is not known, but it is likely a combination of genetic and environmental factors.
• It is a lifelong condition that can result in limited physical function, if not appropriately treated.
• Early treatment can reduce your symptoms and the damage caused to joints.

What is rheumatoid arthritis?

Rheumatoid arthritis is an autoimmune disorder. The immune system attacks the lining of joints, known as the synovium. This leads to inflammation and damage to the underlying bone and cartilage. The inflammation can also affect the skin, kidneys, lungs, heart and blood vessels and other parts of the body.

Causes and risk factors

The exact trigger for rheumatoid arthritis is not known, but it is likely a combination of genetic and environmental factors.

Risk factors for rheumatoid arthritis include:

• Women are three times more likely than men to develop rheumatoid arthritis;
• Genetics: people with specific variants of the human leukocyte antigen (HLA) genes are more likely to develop rheumatoid arthritis;
• Smoking;
• Infection, and;
• Severe stress.

Signs and symptoms

The symptoms of rheumatoid arthritis appear gradually. They include pain, swelling, stiffness and deformity of the joints. The skin over the affected joint may look red.

Rheumatoid arthritis can affect any joint. It usually affects joints symmetrically; that is, if one knee is affected it is likely that the other knee will also show signs of arthritis. The fingers can show characteristic deformities known as swan-neck and boutonnière deformities. Over time, the fingers can also drift outwards towards the little finger.

Rheumatoid arthritis in the fingers. 

Signs and symptoms can vary according to the stage of rheumatoid arthritis:

• Stage I (early stage): inflammation of the synovium (known as synovitis), which causes swelling of affected joints and pain during motion. Joint damage generally does not show up in an X-ray at this stage, except possibly for some soft tissue swelling;
• Stage II (advanced stage): more advanced synovitis, which over time destroys the joint cartilage and results in the narrowing of the joint. This appears on an X-ray as a reduced joint space;
• Stage III (late stage): the synovium becomes abnormally thick due to scar tissue. Damage to the cartilage exposes the underlying bone, which can then also erode. This can be seen on an X-ray; it eventually leads to deformities;
• Stage IV (end-stage): fibrous tissue forms and/or the bones fuse, reducing joint function. Nodules can form under the skin. This stage of rheumatoid arthritis is becoming less common, due to better diagnosis and treatment.
  The changes in the joint and cartilage during the different stages of rheumatoid arthritis. 

Rheumatoid arthritis can also cause signs and symptoms not related to the joints, including:

• Rheumatoid nodules - painless lumps that can form under the skin;
• Nervous system problems such as numbness and tingling;
• Enlarged spleen;
• Inflammation of the blood vessels (vasculitis) which, depending on which blood vessels are affected, can cause a variety of symptoms, and;
• Short breath and a cough due to lung inflammation.

Methods for diagnosis

Your doctor will diagnose rheumatoid arthritis by examining your joints, and by running blood tests:

Clinical features

Indications of rheumatoid arthritis include:

• Three or more swollen joints for six or more weeks;
• Swelling of the same joints on both sides of the body, and;
• Rheumatoid nodules.

Blood tests

Rheumatoid factor

Rheumatoid factor (RF) is an antibody that is found in most people with rheumatoid arthritis, but it can also be detected in people with other illnesses, as well as in some healthy individuals. Up to about 70% of people with rheumatoid arthritis will test positive for rheumatoid factor.

Anti-cyclic citrullinated peptide (anti-CCP) antibody test

This is a more specific test to diagnose rheumatoid arthritis than rheumatoid factor. Anti-CCP can be detected in the blood early in the course of the disease. This test is positive in nearly all people with rheumatoid arthritis.

C-reactive protein and erythrocyte sedimentation rate

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels in the blood indicate the general degree of inflammation in the body. They do not indicate where the inflammation is, or what is causing it. Your doctor may order these tests to determine how active the disease is, or whether a treatment is working. A low CRP or ESR level does not necessarily rule out rheumatoid arthritis, because in some cases inflammation may not be present or active enough to raise the levels above normal.

A blood sample is used to diagnose rheumatoid arthritis. 

Types of treatment

Medications

Non-steroidal anti-inflammatory drugs (NSAIDs)

These are medications that reduce inflammation and pain. As such, they are used to alleviate symptoms in a wide range of conditions, including rheumatoid arthritis. Some examples are ibuprofen, celecoxib and meloxicam.

Disease modifying anti-rheumatic drugs (DMARDs)

These are drugs that act on the immune system to prevent inflammation. They include methotrexate, sulfasalazine and hydroxychloroquine. Their effects are not immediate - they can take weeks or months to be noticed. Unlike NSAIDs, early intervention with DMARDs can slow down disease progression and help reduce damage to joints.

Biologics

Biologics are a subset of DMARDs. They are new drugs that generally work faster than the abovementioned DMARDs. They are generally used if non-biologic therapies are not effective.

Corticosteroids

These are powerful anti-inflammatories. They can be injected directly into the problem joint to minimise the dose needed. However, this will only affect the specific joint targeted, and as rheumatoid arthritis often involves multiple joints, it is often necessary to use oral corticosteroids, such as prednisolone.

The dose and length of time oral corticosteroids are used is generally kept as low as possible to reduce the chance of side effects.

Pain medications (Analgesics)

Some types of pain medications, such as paracetamol, are available without a prescription. Pain medications that require a doctor's prescription, such as oxycodone and fentanyl, are often only needed when the rheumatoid arthritis flares up.

Physiotherapy

Physiotherapy can help by improving mobility, flexibility and strength in arthritic joints.

Surgery

When non-surgical methods fail, an orthopaedic surgeon may perform surgery to:

• Remove damaged tissue;
• Realign the joints;
• Release or repair tendons;
• Remove bone;
• Release trapped nerves;
• Fuse the ends of bones together to reduce joint motion and relieve pain, or;
• Replace a damaged joint with an artificial one.

Potential complications

• When it occurs in the knee, rheumatoid arthritis can cause a Baker's cyst;
• It is common for rheumatoid arthritis to affect the joints in the neck, which can lead to unstable vertebrae that can subsequently slip and damage the spinal cord;
• Sometimes swelling in the wrist compresses a nerve, leading to carpal tunnel syndrome, and;
• In general, inflammation and swelling of any joint results in limited mobility. This can be severe in rheumatoid arthritis, particularly if it is left untreated.

Side effects of medications

Non-steroidal anti-inflammatory drugs

Long-term use of NSAIDs can cause inflammation and ulcers in the digestive tract, and anaemia caused by gastrointestinal bleeding. NSAIDs can also interact with other drugs. If you are taking NSAIDs for arthritis, your doctor or pharmacist will tell you what drugs you should not mix with them. While they are rare, side effects may also include hypertension and heart attack.

DMARDs

DMARDs can have a wide range of side effects, depending on the drug used. Methotrexate can suppress the immune system, leading to an increased risk of infection. Methotrexate can also cause damage to the lungs and liver. If you are prescribed DMARDs, your doctor will closely monitor you for any side effects and potential complications.

Biologics

Biologics can result in the formation of anti-drug antibodies (ADAs), which can make the treatment less effective. Further research is needed to identify the optimal dosage required to reduce the problem of ADA formation. Biologics can also cause immunosuppression, making it harder for the body to fight infections.

Corticosteroids

Long-term use of corticosteroids can lead to weight gain, osteoporosis, immunosuppression, glaucoma, muscle weakness and high blood pressure.

Pregnancy

There are medications that are not safe to use if you are pregnant or planning to get pregnant. If you have rheumatoid arthritis and are considering getting pregnant, talk to an obstetrician (specialist in pregnancy) and your rheumatologist.

For instance, your doctor may advise you to stop taking methotrexate at least a month before you start trying to conceive if you are a woman, and three months if you are a man. If you are a woman taking leflunomide, you need to stop taking it two years before trying to conceive, unless you eliminate the drug from your body using a special course of treatment.

The vast majority of women with rheumatoid arthritis experience a flare-up within the first three months after childbirth. It is usually recommended that you start taking your medications again a few weeks after childbirth. However, some medications, such as methotextrate, cyclosporine and azathioprine, generally should not to be taken while breastfeeding.

Prognosis

Progression of rheumatoid arthritis varies from one individual to another. It can steadily worsen, or sometimes your condition may improve. Symptoms tend to fluctuate.

During pregnancy, rheumatoid arthritis often improves, but it is also common for rheumatoid arthritis to flare up within three months after the birth. In the long term, rheumatoid arthritis can cause permanent damage to the joints, causing chronic pain and a reduction in mobility.

Prevention

It is not possible to prevent rheumatoid arthritis. However, getting diagnosed and treated early can provide the best outcomes, reducing your symptoms and the damage caused to joints.