Arthritis (from Greek arthro-, joint + -itis, inflammation) is a group of conditions that affect the health of the bone joints in the body. One in three adult Americans suffer from some form of Arthritis and the disease affects about twice as many women as men. Arthritic diseases include rheumatoid and psoriatic arthritis, which are autoimmune diseases; septic arthritis, caused by joint infection; and the more common osteoarthritis, or degenerative joint disease. Arthritis can be caused from strains and injuries caused by repetitive motion, sports, overexertion, and falls. Unlike the autoimmune diseases, osteoarthritis largely affects older people and results from the degeneration of joint cartilage. Arthritis may also be caused by gout.

Arthritic joints can be sensitive to weather changes. The increased sensitivity is thought to be caused by the affected joints developing extra nerve endings in an attempt to protect the joint from further damage.

Types of Arthritis

Septic arthritis

Septic arthritis is the proliferation of bacteria in joints and resultant inflammation. Bacteria are either carried by the bloodstream from an infectious focus elsewhere or are introduced by a skin lesion that penetrates the joint.

Septic arthritis should be suspected when one joint (monoarthritis) is affected and the patients is febrile. In seeding arthritis, several joints can be affected simultaneously; this is especially the case when the infection is caused by staphylococcus or gonococcus bacteria.

Diagnosis is by aspiration, Gram stain and culture of fluid from the joint, as well as telltale signs in laboratory testing (such as a highly elevated ESR or CRP).

Therapy is usually with intravenous antibiotics.


Osteoarthritis (or arthrosis) is caused by destruction of the synovium by wear and tear. Contributing factors include congenital hip luxation, obesity, osteoporosis, and diseases such as Perthes' disease .

The main symptoms are pain and restricted movement.

The diagnosis is made on the basis of the history, restricted movement and X-rays of the joint.

The joints mainly affected by osteoarthritis are the hip joints and the knee joints, although in theory any joint in the body can be affected.

Treatment is with NSAIDs or paracetamol, or joint replacement surgery in patients who would otherwise be mobile and do not benefit from medication. Recently glucosamine and chondroitin sulphate have been shown to improve symptoms of osteoarthritis.

Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disorder that causes the body's immune system to attack the bone joints. It is a disabling condition, and often thought of as a disease.

The synovium can become irritated and thickened with this condition, and sometimes it must be surgically removed.

Diagnosis is with immunological studies, such as rheumatoid factor (a specific antibody) which can be negative; when this happens the arthritis is seronegative.

The American College of Rheumatology has defined (1987) the following criteria for Rheumatoid Arthritis [1]:

  • Morning stiffness of >1 hour.

  • Arthritis and soft-tissue swelling of >3 of 14 joints/joint groups

  • Arthritis of hand joints

  • Symmetric arthritis

  • Subcutaneous nodules in specific places

  • Rheumatoid factor at a level above the 95th percentile

  • Radiological changes suggestive of joint erosion

Four criteria have to be met, although many patients are treated despite not meeting the criteria.

Treatment is with NSAIDs, although most patients will proceed to treatment with steroids, DMARDs (disease-modifying antirheumatic drugs), and monoclonal antibodies (anti-TNF-alpha, e.g. infliximab or etanercept). Other therapies are weight loss, physiotherapy and special tools to improve hard movements (e.g. special tin-openers).

Psoriatic Arthritis

Psoriatic arthritis is non-destructive symmetrical inflammation of joints as part of the skin disease psoriasis. It occurs more commonly in patients with tissue type B27. Its treatment is basically identical to that of rheumatoid arthritis.

Gouty Arthritis and Pseudogout

Gout (podagra) is arthritis due to the accumulation of uric acid crystals in the joints. The big toe joint is most commonly affected. Gouty arthritis is immensely painful. The diagnosis is made when crystals are being detected on fluid aspirated from the affected joint, although a clinical diagnosis is often made (i.e. without supporting laboratory evidence).

It is treated in the acute phase with NSAIDs (non-steroidal anti-inflammatory drugs). If attacks happen more than twice a year, allopurinol is often prescribed (although not in the acute phase) to decrease accumulation of uric acid. Colchicine impairs the motility of granulocytes and can prevent the inflammatory phenomena that initiate an attack of gout. Its main side-effects (gastrointestinal upset) can complicate its use. Several other agents are used for gout.

The increased levels of uric acid are often due to increased production or ingestion (many patients blame organ meat such as liver or thymus for attacks) or decreased renal excretion. The latter is worsened by the use of certain (thiazide) diuretics.

Pseudogout (calcium pyrophosphate deposition disease) is very similar disease, but the crystals look differently on light microscopy and the accumulated substance is different.


Arthritis of the hand joints occurs in the iron accumulation disorder hemochromatosis. Its treatment is iron elimination and chelation.

Systemic Lupus Erythematosus

A non-destructive arthritis occurs in lupus erythematosus. Please refer to the main article.

Juvenile Arthritis

Juvenile arthritis typically affects kids before the age of 16. Most kids with juvenile arthritis have a form of rheumatoid arthritis. The symptoms are identical to the adult kind except that in many cases kids outgrow juvenile arthritis.

Familial Mediteranian Fever

Febrile attacks of FMF include arthritis in many patients. Very rare variants areHIDS (hyperimmunoglobulinemia D and periodic fever syndrome) and TRAPS (TNF-alpha receptor associated periodic fever syndrome).

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