Risk Factors
A range of environmental and genetic variables have been evaluated as potential risk factors for RA (e.g. hormonal exposures, tobacco use, dietary components, HLA genotype, and microbial exposures), but to date no definitive risk factors for RA have been identified.
Of the environmental factors examined, the most consistent evidence exists for an association between tobacco use and RA; most studies of this risk factor have found a history of smoking is associated with RA onset with increased risks ranging from 1.3 to 2.4.
The role of the following four estrogenic factors in RA etiology has been studied extensively:
- Oral contraceptives(OC) — Early studies found a decreased risk of RA among women who had ever used OCs, a relationship that has not been confirmed in recent studies.
- Hormone replacement therapy (HRT) — There is mixed evidence of an association between HRT and RA onset.
- Live birth history — Most studies have found that women who have never had a live birth have a slight to moderately increased risk of RA.
- Breastfeeding — The most recent studies have found that RA is less common among women who breastfeed; this is in contrast with earlier studies which found an increased risk associated with breastfeeding.
- Genetic susceptibility markers. Most attention has been given to the DR4 and DRB1 molecules of the major histocompatability complex HLA class II genes. The strongest associations have been found between RA and the DRB10401 and DRB10404 alleles.
Diagnosis
The 1987 American College of Rheumatology criteria are used in the clinical diagnosis of RA, and to define RA in epidemiologic studies. Persons must meet four of seven ACR criteria; these criteria are based on clinical observation (e.g., number of joints affected), laboratory tests (e.g., positive rheumatoid factor), and radiographic examination (e.g., X-rays evidence of joint erosion).
Early RA is typically defined as RA that is diagnosed within 6 months of symptom onset. There is extensive interest in early diagnosis of RA because early treatment may improve disease prognosis. The only U.S. study to examine time between symptom onset and diagnosis reported a median lag time of approximately 4 weeks between symptom onset and medical encounter, and a median time of 18 weeks between medical encounter and RA diagnosis (A total median lag time of 36 weeks)6. These authors noted that there was even a delay in diagnosing patients with most identifiable features of RA (e.g., morning stiffness and seropositive rheumatoid factor), and concluded that early disease recognition is challenging as only half of those who eventually develop RA initially present with features specific to the condition.
What causes RA?
The cause of rheumatoid arthritis is still unknown. All though infectious diseases such as bacteria, fungus and viruses have been suspected to cause rheumatoid arthritis none have actually been proven to cause it. Scientists all over the world are researching the cause of rheumatoid arthritis. It is currently believed that rheumatoid arthritis is genetically inherited. Another suspect cause of is that certain infections or environmental factors may trigger the activation of the immune system in individuals who are susceptible. If this is the case the misdirected immune system then attacks the body’s own tissues. This eventually leads to inflammation in the joints and at times the organs of the body such as eyes or lungs.
Despite not knowing the exact trigger the result is the same. The immune system begins to inflame the joints as well as other tissues in the body. Immune cells are activated and the chemical messengers are expressed into the inflamed areas.
It is also known that environmental factors have an impact in causing rheumatoid arthritis. One example of this is scientists reporting that smoking tobacco can increase the risk of developing rheumatoid arthritis.
Overview
Rheumatoid arthritis is a systemic inflammatory disease which manifests itself in multiple joints of the body. The inflammatory process primarily affects the lining of the joints (synovial membrane), but can also affect other organs. The inflamed synovium leads to erosions of the cartilage and bone and sometimes joint deformity. Pain, swelling, and redness are common joint manifestations. Although the definitive causes are unknown, RA is believed to be the result of a faulty immune response. RA can begin at any age and is associated with fatigue and prolonged stiffness after rest. There is no cure for RA, but new drugs are increasingly available to treat the disease. In addition to medications and surgery, good self-management, including exercise, are known to reduce pain and disability.
All Doctors - Rheumatoid Arthritis
Orthopedic Surgery, Orthopedics, Rheumatology, Surgery
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Internal Medicine, Rheumatology
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Internal Medicine, Orthopedics, Rheumatology
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Internal Medicine, Rheumatology
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Internal Medicine, Rheumatology
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Internal Medicine, Rheumatology
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Internal Medicine, Rheumatology
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Internal Medicine, Rheumatology
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The Arthritis Foundation has been the voice for people with arthritis and their families for more than 50 years. The Arthritis Foundation is the only national not-for-profit organization that supports the more than 100 types of arthritis and related conditions with information, services, and research. Through its chapters, the Arthritis Foundation provides community-based programs such as the Arthritis Foundation Self-Help Program, Arthritis Foundation Exercise Program, and the Arthritis Foundation Aquatics Program.
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