Arthritis

Arthritis is a condition where the smooth layer that helps joints move easily wears away, causing the bones to rub together. This can make moving painful and difficult. Common signs include joint pain, stiffness, swelling, and warmth around the joint. Sometimes, other parts of the body like the skin can also be affected.

There are many types of arthritis. The two most common are osteoarthritis, which usually happens as people get older and often affects joints like the hips, knees, and fingers, and rheumatoid arthritis, which is a disorder where the body's immune system attacks the joints, often affecting the hands and feet. Other types include gout, lupus, and septic arthritis.

Treating arthritis early can help manage symptoms. This might include resting the affected joint, applying heat or ice, losing weight, and exercising. Medicines such as ibuprofen and paracetamol can help with pain and swelling. In severe cases, surgery to replace the joint may be needed. Arthritis is very common, especially as people age, and it can make it hard to do everyday tasks or work.

Classification

When someone talks about having "arthritis," it usually means they have one of several diseases that cause joint pain. Common types include Osteoarthritis, Rheumatoid arthritis, and Gout. Joint pain can also be a sign of other health problems, like Psoriasis or Lyme disease. Sometimes, a person might have joint pain that doesn’t clearly fit into any specific disease, which doctors call undifferentiated arthritis.

Signs and symptoms

Pain is a common sign of arthritis, and it can range from mild to severe. Other signs include swelling, stiffness, redness, and aching around the joints. Some types of arthritis, like lupus and rheumatoid arthritis, can also affect other parts of the body. This might make it hard to use the hand or walk, cause stiffness in joints, lead to rashes or itching, make someone feel very tired or weak, result in weight loss, disrupt sleep, cause muscle aches, and make joints feel tender or hard to move.

Causes

Several things can lead to arthritis, and it depends on the type.

Osteoarthritis happens when the smooth part in joints, called cartilage, gets damaged from old injuries or just wearing down over time. This can make the bones rub together, causing pain and stiffness.

In rheumatoid arthritis, the body’s defense system, called the immune system, mistakenly attacks the joints, making them swollen and painful.

Gout is another type of arthritis caused by too much uric acid in the blood. This can lead to sharp pain, especially in the toes, because tiny crystals form in the joints. Eating certain foods or other body factors can increase uric acid levels.

Other types of arthritis include ankylosing spondylitis, juvenile idiopathic arthritis, psoriatic arthritis, and reactive arthritis, among others.

Risk factors

Some things can make it more likely that a person will develop arthritis when they get older. Not all of these things can be changed, but some can.

Having more weight than is healthy, getting hurt on a joint before, or the type of joint a person has can increase the chance of developing a type of arthritis called osteoarthritis. For another type of arthritis called inflammatory arthritis, things like being a girl, having family members with arthritis, being older, having more weight than is healthy, past joint injuries, and being around cigarette smoke can increase the chance of getting it.

Smoking has also been linked to a higher chance of developing certain types of arthritis.

Diagnosis

Diagnosis is made by a health professional through a clinical examination, and may be supported by tests such as imaging and blood tests, depending on the type of suspected arthritis. Pain patterns may vary depending on the type of arthritis and the location. Rheumatoid arthritis is generally worse in the morning and associated with stiffness lasting over 30 minutes. With osteoarthritis, the pain tends to initially be related to activity and then becomes more constant over time.

Important features to look out for include the rate of onset of symptoms, pattern of joint involvement, symmetry of symptoms, early morning stiffness, associated tenderness around the joint, locking of joint with inactivity, aggravating and relieving factors, and presence of systemic symptoms.

Physical examination may include observing the affected joints, evaluating gait, and examining the skin for findings that could be related to rheumatological disease or lung inflammation. Physical examination may confirm the diagnosis or may indicate systemic disease. Chest X-rays are often used to follow progression or help assess severity.

Screening blood tests for suspected arthritis include rheumatoid factor, antinuclear factor (ANF), extractable nuclear antigen, and specific antibodies.

Rheumatoid arthritis patients often have elevated erythrocyte sedimentation rate (ESR, also known as sed rate) or C-reactive protein (CRP) levels, which indicates the presence of an inflammatory process in the body. Anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor (RF) are two more common blood tests when assessing for rheumatoid arthritis.

Imaging tests like X-rays are commonly utilized to diagnose and monitor arthritis. Other imaging tests for rheumatoid arthritis that may be considered include CT scanning, PET scanning, bone scanning, and DEXA.

Osteoarthritis

Main article: Osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis. It affects humans and other animals like dogs, cats, and horses. It can affect both the larger joints (i.e. knee, hip, shoulder, etc.) and the smaller joints (i.e. fingers, toes, foot, etc.) of the body. Caused by daily wear and tear of the joint, this can speed up its progression. OA results from cartilage breakdown, leading to bones rubbing directly and eroding each other. The symptoms typically begin with minor pain during physical activity, but can eventually progress to be present at rest. The pain can be debilitating and prevent one from doing activities that they would normally do as part of their daily routine. OA typically affects the weight-bearing joints, such as the back, knee and hip. Unlike rheumatoid arthritis, OA is more common in the elderly, with increased age being the strongest predictor. Over 30 percent of women have some degree of OA by age 65. Diagnosis consists of the primary tools for diagnosing OA are X-rays of the joint. Findings on X-ray that are consistent with OA include those with joint space narrowing (due to cartilage breakdown), bone spurs, sclerosis, and bone cysts.

Rheumatoid arthritis

Main article: Rheumatoid arthritis

Rheumatoid arthritis (RA) is a disorder in which the body's own immune system starts to attack body tissues specifically the cartilage at the end of bones known as articular cartilage. The attack is not only directed at the joint but to many other parts of the body. RA often affects joints in the fingers, wrists, knees and elbows, is symmetrical (appears on both sides of the body), and can lead to severe progressive deformity in a matter of years if not adequately treated. RA usually onsets earlier in life than OA and commonly effects people aged 20 and above. In children, the disorder can present with a skin rash, fever, pain, disability, and limitations in daily activities. With earlier diagnosis and appropriate aggressive treatment, many individuals can obtain control of their symptoms leading to a better quality of life compared to those without treatment.

One of the main triggers of bone erosion in the joints in rheumatoid arthritis is inflammation of the synovium (lining of the joint capsule), caused in part by the production of pro-inflammatory cytokines and receptor activator of nuclear factor kappa B ligand (RANKL), a cell surface protein present in Th17 cells and osteoblasts. Osteoclast activity can be directly induced by osteoblasts through the RANK/RANKL mechanism.

Lupus

Main article: Lupus erythematosus

Lupus is an autoimmune collagen vascular disorder that can be present with severe arthritis. In fact, about 90% of patients with Lupus have musculoskeletal involvement. Symptoms in these patients can often mimic those of rheumatoid arthritis with similar stiffness and pain patterns. Joints in the fingers, wrist, and knee tend to be the most affected. Other features commonly seen in patients with Lupus include a skin rash, extreme photosensitivity, hair loss, kidney problems, and shortness of breath secondary to scarring that occurs in the lungs.

Gout

Main article: Gout

In the early stages of gout, usually only one joint is affected; however over time, many joints can become affected. Gout most commonly occurs in joints located in the big toe, knee, and/or fingers. During a gout flare, the affected joints often become swollen with associated warmth and redness. The resulting pain can be significant and potentially debilitating. When one of these flares occurs, management involves the use of anti-inflammatories, such as NSAIDs, colchicine, or glucocorticoids. In between gout flares, it is recommended that patients take medications that decrease the production of uric acid (i.e. allopurinol, febuxostat) or increase the elimination of uric acid from the body (i.e. probenecid).

Gout has been associated with excessive intake of alcohol and food, such as red meat. Thus, it is also recommended that patients with gout adhere to a diet rich in fiber, vegetables, and whole grains, while limiting the intake of alcohol and fatty foods.

There is also an uncommon form of gout that is known as pseudogout, which is caused by the formation of calcium pyrophosphate crystals in the joint. Unlike gout, no targeted treatments are currently available. At this time, management is aimed at decreasing inflammation in order to reduce the intensity and frequency of flares.

Comparison of types

Other

Infectious arthritis is another severe form of arthritis that is sometimes referred to as septic arthritis. It typically occurs when a patient is ill or has an infection. Common symptoms include the sudden onset of chills, fever, and joint pain. The condition is caused by bacteria that spread through the blood stream from elsewhere in the body. This bacteria can travel to specific joints and start to erode cartilage. Infectious arthritis must be rapidly diagnosed and treated promptly in order to prevent irreversible joint damage. Only about 1% of cases of infectious arthritis are a result of viruses. Within recent years, the virus SARS-CoV-2, which causes COVID-19, has been added to this list. SARS-CoV-2 tends to cause reactive arthritis rather than local septic arthritis.

Psoriasis can develop into psoriatic arthritis. With psoriatic arthritis, most individuals first develop skin symptoms (such as scaly patches and itchiness) and then begin to experience joint related symptoms. They typically experience continuous joint pain, stiffness and swelling like other forms of arthritis. This disease can go into remission, but there is currently no known cure for the disorder. Treatment current revolves around decreasing autoimmune attacks with immune suppressive medications. A small percentage of patients with psoriatic arthritis can develop a severely painful and destructive form of arthritis which destroys the small joints in the hands and sometimes lead to permanent disability and loss of hand function.

Treatment

There is no known cure for arthritis, but there are ways to help manage the pain and improve movement. Treatment can include physical therapy, exercise, special braces, and different kinds of medicines. In some cases, surgery to replace a joint may be needed to fix damage and help a person move more easily.

Physical therapy and exercise can be very helpful for people with arthritis. These activities can make joints more flexible, reduce pain, and delay the need for surgery. Doctors may also suggest special tools to help with daily tasks, making life easier for those with arthritis.

Epidemiology

Arthritis is more common in older people, but it can also affect children. It occurs more often in women than in men and affects people from all backgrounds. In the United States, many adults have been diagnosed with arthritis, and this number is expected to grow as the population ages. People who have other health issues, like heart disease or diabetes, are more likely to have arthritis.

Disability from muscle and bone disorders has increased over time, with osteoarthritis being one of the fastest-growing conditions. Information about arthritis in Africa is limited, but studies show that different types of arthritis occur there as well. For example, rheumatoid arthritis, osteoarthritis, and other forms have been found in various regions across the continent.

History

People have had arthritis for a very long time. Scientists have found signs of arthritis in dinosaurs and in very old human bones. One of the earliest known cases was found in bones from about 4500 BC. Arthritis has been found in many places throughout history, including in ancient Italy and Austria.

In the 1700s, a doctor named William Musgrave wrote one of the first books about arthritis. Another doctor in France, Augustin Jacob Landré-Beauvais, was the first to describe the symptoms of a type of arthritis called rheumatoid arthritis. In the 1960s, a surgeon named John Charnley performed the first hip replacement to help treat arthritis.

Society and culture

Arthritis is a leading reason why people in the United States have trouble doing everyday activities. Over 20 million people with arthritis find it hard to move and do things they normally would. Because of this, many miss out on work or school and need to see a doctor often. Arthritis can make it tough to stay active, and some people might even need to stay at home. The cost of dealing with arthritis is very high, around $100 billion, with a big part of that money coming from people not being able to earn as much.

Terminology

The word "arthritis" comes from two parts: "arthr-" from the Ancient Greek word for "joint," and "-itis," a suffix that means "pertaining to" or often linked with swelling and redness in the body.

The term "arthritides" is just the plural form of arthritis, used to talk about all the different conditions that are similar to arthritis.