EPG Arthritis Knowledge Centre
Understanding Arthritis
Rheumatoid Arthritis
Complications of Rheumatoid Arthritis
Raptured tendons
Joint infection
Ruptured joints, e.g. Baker’s cysts
Spinal cord compression
Amyloidosis
Rheumatoid arthritis is a chronic symmetrical polyarthritis of unexplained cause. It is a systematic disorder characterized by chronic inflammatory synovitis of mainly peripheral joints. Its course is extremely variable and it is associated with nonarticular features.
AETIOLOGY AND PATHOGENESIS
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Geographical. RA has a worldwide distribution and affects 1–3% of the population. It is a significant cause of disability and mortality and carries a high socio-economic cost.
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Age. RA represents from early childhood (when it is rare) to late old age. The most common age of onset is between 30 and 50 years.
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Sex. Women before the menopause are affected three times more often than men. After the menopause the frequency of onset is similar between the sexes, suggesting an aetiological role for sex hormones.
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Familial. The disease is familial but sporadic. In occasional families it affects several generations. The genetic contribution is estimated at 15–30%.
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HLA types. There is a strong association between susceptibility to RA and certain HLA haplotypes. HLA-DR4, which occurs in 50-75% of patients, correlates with a poor prognosis and the possession of a specific pentapeptide in the third allelic hypervariable region of HLA-DRβ-1 chain increases susceptibility.
Typical Presentations of Rheumatoid Arthritis
Palindromic – Monarticular attacks lasting 24-48 hours; 50% progress to other types of RA.
Transient – A self-limiting disease, lasting less than 12 months and leaving no permanent joint damage. Usually seronegative for lgM rheumatoid factor. Some of these may be undetected post viral arthritis.
Remitting – There is a period of several years during which the arthritis is active but then remits, leaving minimal damage.
Chronic, persistent – The most typical form. It may be seropositive or seronegative for lgM rheumatoid factor. The disease follows a relapsing and remitting course over many years. Seropositive patients tend to develop greater joint damage and long-term disability.
Rapidly progressive – The disease progresses remorselessly over a few years and leads rapidly to severe joint damage and disability. It is usually seropositive, has a high incidence of systematic complications and is difficult to treat.
Reference for content:
Kumar, P and Clark, M: Clinical Medicine. (4th Edition). London, W.B. Saunders, Harcourt Publishers Ltd, (1998).