Rheumatoid arthritis
BMJ 2016; 352 doi: https://doi.org/10.1136/bmj.i387 (Published 23 March 2016) Cite this as: BMJ 2016;352:i387
Chinese translation
该文章的中文翻译
- Kate Harnden, foundation year 1 doctor1,
- Colin Pease, consultant rheumatologist2,
- Andrew Jackson, general practitioner3
- 1St James’ University Hospital, Leeds LS9 7TF, UK
- 2Rheumatology, Chapel Allerton Hospital, Leeds LS7 4SA, UK
- 3Bingley Medical Practice, Canalside Health Care Centre, Bingley BD16 4RP, UK
- Correspondence to: K Harnden kateharnden{at}doctors.org.uk
What you need to know
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Consider rheumatoid arthritis in any patient presenting with joint pain, swelling, and morning stiffness of over 30 minutes
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Refer within two weeks if symptoms affect small joints of the hands or feet, or more than one joint, or have been present for at least three months
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Starting treatment with combination disease-modifying antirheumatic drugs (including methotrexate), especially within three months of symptom onset, can slow disease progression and improve symptoms, function, and quality of life
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When rheumatoid arthritis is suspected, x ray symptomatic joints and measure rheumatoid factor, erythrocyte sedimentation rate, and C reactive protein without delaying referral, as negative results do not exclude the diagnosis
A 43 year old woman with six weeks of bilateral wrist pain is diagnosed with repetitive strain injury. Five weeks later, she returns with worsening pain. On further questioning, she reports increasing fatigue and two hours of morning stiffness in her hands. Examination reveals bilateral wrist and metacarpophalangeal joint swelling. She is referred to a rheumatologist, who diagnoses rheumatoid arthritis and initiates treatment.
What is rheumatoid arthritis?
Rheumatoid arthritis is an autoimmune, polyarticular arthritis characterised by progressive joint destruction and deformity, usually of peripheral joints (box 1). Its cause is unknown, and extra-articular organ involvement such as interstitial lung disease and Sjögrens syndrome may occur. Appropriate early therapy improves symptoms, function, and mortality, and may reduce comorbidities.
Box 1: How common is rheumatoid arthritis?
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In a 2010 systematic review, estimated prevalence in North America and Northern Europe was between 0.5% and 1.1%. Developing countries have a lower prevalence (0.1-0.5%)1
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Rheumatoid arthritis is more common in women (3:1 female:male ratio).1 It can present at any age, but in a retrospective cohort study the mean age of onset was 55.6 years2
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The number of new cases identified in the UK each year is around 20 000.3 An average UK general practitioner will therefore see one new case every two years
Why is it missed?
Observational studies in England, Europe, and the United States all report delayed referral by general practitioners. A 2009 National Audit Office report found that patients in England with undiagnosed rheumatoid arthritis visited their general practitioner an average of four times before being referred; 18% visited over eight times.4 Detecting early rheumatoid arthritis is difficult as musculoskeletal problems are common in general practice. Clinical signs may be subtle, inflammatory markers such as erythrocyte sedimentation rate and C reactive protein are often normal, and more specific markers are also often negative (31% of patients are seronegative for rheumatoid factor and 33% are negative for anti-CCP (cyclic citrullinated peptide) antibodies).5
Why does it matter?
The disability created by rheumatoid arthritis causes 28% of patients to give up their job within a year.6 There is a three month “therapeutic window of opportunity,” from symptom onset in which treatment can delay disease progression.7 Delaying treatment after this window has been shown to increase radiographic damage and mortality.7 8 Furthermore, a treatment delay of 3-6 months will make monotherapy less potent at inducing drug free remission.9
How is it diagnosed?
Clinical features
The main symptoms are:
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Joint pain, swelling, and stiffness, commonly affecting wrists, proximal interphalangeal, metacarpophalangeal, and metatarsophalangeal joints.
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Early morning stiffness that lasts over 30 minutes (sensitivity 74-77%, specificity 48-52%10)
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Systemic symptoms such as weight loss, fatigue (84% of patients at presentation in an observational study11) and malaise.
Features on examination include:
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Swelling of three or more joints (specificity of 73%12)
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Tenderness largely along the joint line
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Synovitis, producing a “boggy” or “doughy” swelling, which may be subtle
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A positive “squeeze test”—pain on gently squeezing the metacarpophalangeal or metatarsophalangeal joints together (fig 1⇓) (sensitivity 40-48% but specificity 84% for early disease12).
Fig 1 Squeeze test of (A) metacarpophalangeal and (B) metatarsophalangeal joints (adapted from Arthritis Research UK www.arthritisresearchuk.org/arthritis-information/inflammatory-arthritis-pathway/step-one.aspx)
Synovitis of the wrist of flexor tendons may also present with carpal tunnel symptoms such as pain and paraesthesia along the distribution of the median nerve.
Box 2 outlines the indications for referral.
Box 2: When to refer (based on National Institute for Health and Care Excellence (NICE) guidance13)
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Refer anyone with suspected persistent, unexplained synovitis to rheumatology
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Refer within two weeks if:
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Small joints of the hands or feet are affected
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More than one joint is affected
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At least three months have elapsed between symptom onset and presentation
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Investigations
If rheumatoid arthritis is suspected, refer within two weeks to rheumatology and request the following blood tests without delaying referral: rheumatoid factor (69% sensitive and 85% specific5), erythrocyte sedimentation rate, and C reactive protein. If rheumatoid factor is negative, consider requesting a test for anti-CCP antibodies, which has similar sensitivity to rheumatoid factor (67%) but is more specific (95%).5 14
X ray the hands and feet if symptomatic without delaying referral, as erosive damage may be present, despite other investigations being normal. Ultrasound may be more sensitive for early synovitis, but its availability is limited in the UK.13 15
How is it managed?
In the UK, early arthritis clinics have been set up to assess and treat patients with suspected rheumatoid arthritis.
Initial treatment involves offering a combination of disease-modifying antirheumatic drugs (methotrexate, sulphasalazine, etc) as soon as possible to slow disease progression and improve symptoms, function, and quality of life.13 Glucocorticoids, given intra-articularly, intramuscularly, or orally, provide quick, short term symptom relief and may slow joint damage. However, referring general practitioners should offer a glucocorticoid trial only if the patient is unlikely to be seen promptly in secondary care, as the drugs can make confirmatory diagnosis difficult. Annual review by general practitioners should include checking for and managing comorbidities such as cardiovascular disease, osteoporosis, and depression.13
How patients were involved in the creation of this article
We sought the opinion of a patient with rheumatoid arthritis, who described how her initial diagnostic process had been frustrating, with multiple visits to her general practice. She stated how essential a diagnosis had been in helping her manage and come to terms with the condition. Her comments about the importance of early diagnosis and appropriate management were taken into account when drafting the article.
Footnotes
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This is one of a series of occasional articles highlighting conditions that may be more common than many doctors realise or may be missed at first presentation. The series advisers are Anthony Harnden, professor of primary care, Department of Primary Care Health Sciences, University of Oxford, and Richard Lehman, general practitioner, Banbury. To suggest a topic for this series, please email us at practice@bmj.com.
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Contributors: KH had the original idea for the article and researched the literature. All authors contributed towards planning and drafting the article. KH is guarantor.
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Competing interests: We have read and understood the BMJ policy on declaration of interests and declare the following interests: CP is treasurer of the British Society for Rheumatology; AJ is employed within a Federation owned community musculoskeletal service within sessions that he is paid for and he is a shareholder in profits made. Employed on an ad hoc basis as an RCGP musculoskeletal tutor.
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Provenance and peer review: Not commissioned; externally peer reviewed.