‘Rheumatism’ is the colloquial term for non-specific musculoskeletal symptoms arising in the joints, ligaments, tendons and muscles. ‘Arthritis’ describes a pathological musculoskeletal disorder, usually inflammatory in nature. Most common are sprains of ligaments, strains of tendons and muscles, BURSITIS, TENDINITIS and non-specific back pain (see BACKACHE).
rarely starts before 40, but by the age of 80 affects 80 per cent of the population. There are changes in the articular cartilage, tendons and ligaments. OA is not purely ‘wear and tear’ because it involves active inflammation. Early OA may be precipitated by localised alteration in anatomy, such as a fracture or infection of a joint. Reactive new bone growth typically occurs, causing sclerosis (hardening) beneath the joint, and osteophytes – outgrowths of bone – are characteristic at the margins of the joint. The most common sites are the first metatarsal (great toe), spinal facet joints, the knee, the base of the thumb and the terminal finger joints (Heberden's nodes).
OA has a slow but variable course, with periods of pain and low-grade inflammation.
results from crystallisation of URIC ACID in joints, against a background of hyperuricaemia, a high concentration of uric acid in the blood. This may result from genetic and environmental factors, such as certain dietary factors, alcohol or diuretic drugs.
is less common than OA, but potentially much more serious. Several types exist, including:
This affects younger men, chiefly involving spinal and leg joints. It may lead to inflammation and eventual ossification of the enthesis – that is, where the ligaments and tendons are inserted into the bone around joints. This may be associated with disorders in other parts of the body: skin inflammation (PSORIASIS), bowel and genito-urinary inflammation, sometimes resulting in infection of the organs (such as dysentery). The syndromes most clearly delineated are ankylosing spondylitis (see SPINE AND SPINAL CORD, DISEASES AND INJURIES OF), psoriatic or colitic spondylitis, and REITER'S SYNDROME. The diagnosis is made clinically and radiologically; no association has been found with autoantibodies (see AUTOANTIBODY). A particularly clear gene locus, HLA B27, has been identified in ankylosing spondylitis. Psoriasis can be associated with a characteristic peripheral arthritis.
(see AUTOIMMUNE DISORDERS).
See also main entry for RHEUMATOID ARTHRITIS. The most common of these diseases. Acute inflammation causes lymphoid SYNOVITIS leading to erosion of cartilage, associated joints and soft tissues. Fibrosis follows, causing deformity. Blood tests show that autoantibodies are common, particularly rheumatoid factor. A common complication of RA is SJÖGREN'S SYNDROME, in which inflammation of the mucosal glands may result in a dry mouth and eyes.
and various overlap syndromes occur, such as systemic sclerosis and dermatomyositis. Autoantibodies against nuclear proteins such as DNA lead to deposits of immune complexes and VASCULITIS in various tissues, such as kidney, brain, skin and lungs. This may lead to various symptoms, and sometimes even to organ failure.
includes:
An uncommon but potentially very joint-damaging condition if not diagnosed and treated early with appropriate antibiotics. It is caused by bacterial such as staphylococci (see STAPHYLOCOCCUS) and, rarely in developed countries, the TUBERCLE bacillus. Particularly at risk are the elderly and the immunologically vulnerable, such as those under treatment for cancer, or on CORTICOSTEROIDS or IMMUNOSUPPRESSANT drugs.
Now rare in Western countries. Resulting from an immunological reaction to a streptococcal infection, it is characterised by arthritis that flits from joint to joint over a period of days or weeks, rash and cardiac involvement.
Septic arthritis is the only type that is treated with antibiotics, while the principles of treatment for the others are similar: to reduce risk factors (such as hyperuricaemia in gout); to suppress inflammation; to improve function with physiotherapy; and, in the event of joint failure, to perform surgical arthroplasty. NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) include aspirin, paracetamol and many recently developed ones, such as the proprionic acid derivatives IBUPROFEN and naproxen, along with other drugs that have similar properties such as PIROXICAM. They all carry a risk of toxicity, such as renal dysfunction, or gastrointestinal irritation with haemorrhage. Stronger suppression of inflammation requires corticosteroids and CYTOTOXIC drugs such as azathioprine or cyclophosphamide. Recent research promises more specific and less toxic anti-inflammatory drugs, such as the monoclonal antibodies like infliximab. An important treatment for some osteoarthritic joints is surgical replacement of the joints.