Rheumatoid Arthritis
Introduction
Features of inflammatory arthritis
- Pain and stiffness worse in the morning and after rest
- Early morning pain and stiffness may last several hours (in OA, duration is much shorter)
- Inflammatory markers (ESR, CRP) usually raised
- Often accompanied by normochromic, normocytic anaemia
This is a
chronic symmetrical arthritis. When we say it is symmetrical, we don’t necessarily mean a mirror image, just that the
same joints are affected on both sides of the body. it is also important to remember that RA is a systemic condition,
with many extra-articular manifestations.
Typically it affects the peripheral joints, and there is inflammation of the joint (synovitis). Deformity is common and the course is extremely variable.
Epidemiology and Aetiology
- affects 0.5-3% of the population worldwide
- can present at any age (from childhood to old age), but the peak incidence is between 30-50 years
- women affected more than men (M:F – 1:2)
- before the menopause, risk is 3x higher for women
- after the menopause it is equal
- suggests sex hormones involved in some way
- the contraceptive pill can delay the onset, but does not reduce the risk
- Genetic factors are involved. Certain HLA variants are implicated, especially in severe forms of the disease:
- HLA-DR4 – occurs in 50-75% of patients, and is associated with a particularly poor prognosis
- HLA-DR1 is another variant associated with RA, and poor prognosis
- Environmental factors:
Clinical features
Most commonly, the condition will present as progressive over weeks to months. These patients have the worse prognosis. But in some cases it can come on in days, or even overnight. Also, it is almost always a
polyarthritis, but some cases do present as monoarthritis, most commonly of the knee or shoulder, or with
carpal tunnel syndrome.
- symmetrical swollen distal joints
- Often warm and tender joints
- sometimes presents as a sudden onset of widespread arthritis, but this is rare.
- Typically the joint of the hand (MCP, DIP and PIP’s)and the distal metatarsals of the foot.
- Sometimes it affects the wrists, elbows, shoulders, knees and ankles.
- Hips are very rarely affected
- Limitation of movement
- Muscle wasting
- Pain and stiffness – worse in the morning, may improve with activity. It is often described as an ache type pain.
- Disturbed sleep
- Nodules – in the early and mild stages of the disease, there are relatively few inflammatory cells in the joints. As the disease progresses, these increase in number and there may be nodular masses of inflammatory cells within the joint. Rheumatoid nodules occur when these inflammatory cells form similar inflammatory structures outside of the joint capsules. The nodules are usually pink/red and have a rubbery texture. They are painless. You should always check the elbows in a hand exam, looking for rheumatoid nodules!
- Osteoporosis – often occurs in the bones immediately around the affected joints, particularly in the fingers. This may be the first sign of RA.
- Secondary Osteoarthritis
- Deformity – as the joint capsule is destroyed, and the articular surface damaged, deformity occurs. Specific examples include
-
$(function(){
var pertama = $('#herb-dict .herblist li:first-child').attr('class');
$('#herb-dict .herblist li.'+pertama).show();
$('#herb-dict .alphlist li#'+pertama+' a').addClass('active');
$('#herb-dict .alphlist li a').click(function(){
var target = $(this).attr('rel')
$('#herb-dict .herblist li').hide();
$('#herb-dict .herblist li.'+target).show();
$('#herb-dict .alphlist li a').removeClass('active');
$(this).addClass('active');
});
});
