Rheumatoid arthritis: Clinical sciences

Chapters:

Watch video only

Introduction0:00–0:32

Rheumatoid arthritis is a chronic, autoimmune disorder that involves symmetric inflammation of the synovial joints, leading to joint effusion with eventual destruction of cartilage and bones.
This results in joint pain and severe functional impairment of the affected joints. Since there are no pathognomonic laboratory or imaging findings associated with rheumatoid arthritis, the diagnosis is clinical, meaning it is based on historical and physical exam findings.Now, if your patient presents with signs and symptoms suggestive of rheumatoid arthritis, first you should obtain a focused history and physical exam.

Focused H&P0:32–3:04

Your patient may report joint stiffness in the morning, or with prolonged inactivity, that lasts 30 minutes or longer, as well as joint swelling.
Additionally, there might be nonspecific systemic symptoms such as fatigue, malaise, and depressed mood, as well as poor appetite.
Patients usually report that these symptoms have been ongoing for more than 6 weeks.Physical exam findings typically include symmetrical swelling and joint tenderness to palpation of the smaller joints.
The most commonly affected joints are the proximal interphalangeal or PIP joints, and metacarpophalangeal or MCP joints.
Typically, if one hand is involved, it is likely the other hand is also involved. You may also find swelling and tenderness of the wrists and metatarsophalangeal, or MTP, joints.
Keep in mind that sometimes larger joints can also be involved. When a larger joint is affected, you might also notice a joint effusion.
Now, here’s a clinical pearl to keep in mind! If your patient has less than 30 minutes of morning stiffness, then consider mechanical wear and tear, like osteoarthritis instead of rheumatoid arthritis, where the stiffness can last more than 30 minutes.
Another way to distinguish between the two is by the pattern of affected joints. Rheumatoid arthritis tends to be symmetric, meaning that joints on both sides of the body are equally affected, whereas patients with osteoarthritis are more likely to have asymmetric joint involvement.Now, if the disease has been present for some time, the underlying joint inflammation can cause the surrounding structures to shorten, stiffen, and become constricted, which eventually results in contractures.
Some important contractures to keep in mind when approaching a patient with rheumatoid arthritis include ulnar deviation of the MCP joints; Boutonniere deformities, where there is persistent flexion of the PIP joints and hyperextension of the DIP joints; and Swan-neck deformities, where there is persistent hyperextension of the PIP joints and flexion of the DIP joints.
All of these findings are highly suggestive of rheumatoid arthritis, so at this point, you can make the diagnosis.Now, here’s another clinical pearl to keep in mind!
Rheumatoid arthritis is characterized by polyarthritis, or having multiple joint involvement. If you only find one joint with arthritis, or monoarticular arthritis, you should consider another diagnosis, such as septic arthritis or gout.
Alright, once you’ve diagnosed rheumatoid arthritis, your next step should be to determine the disease prognosis and severity.

Prognosis and severity3:04–4:04

To do so, you have to order labs, including CBC, antinuclear antibody, or ANA; anti-cyclic citrullinated peptide, or anti-CCP antibody; rheumatoid factor, or RF; ESR; and CRP.
Next, order imaging, including an X-ray of the affected joints. Depending on your concern for other conditions, you can also order an ultrasound of the affected joints to evaluate for evidence supporting another diagnosis.
For example, abscess formation indicates septic arthritis. If a large joint is involved, you might also need to perform an arthrocentesis with cell count, gram stain, cultures, and crystal analysis.
Remember, this lab and imaging workup is not diagnostic, but prognostic, and results will help you determine disease severity and risk.
Alright, now moving on to the lab findings, which may reveal anemia of chronic disease and thrombocytosis on CBC. You may also find a positive ANA, anti-CCP, or RF, but negative values do not rule out rheumatoid arthritis.

Lab findings, imaging, synovial fluid results4:04–5:55

A negative ANA does rule out systemic lupus erythematosus, also called SLE, however. Finally, ESR and CRP could be normal or elevated!Now, here’s a clinical pearl to keep in mind!
Anti-CCP and RF are antibodies that define a patient with rheumatoid arthritis as “seropositive”. Seropositive individuals are at higher risk for disease complications, like bony erosions.
Though they are part of the classification criteria, they are not required to make the diagnosis of rheumatoid arthritis, as some patients are “seronegative”.
For example, RF is also seen in conditions like infections, malignancies, and even healthy individuals without organic disease.
As far as the imaging goes, An X-ray might reveal classic findings like ulnar deviation of the MCPs, periarticular soft tissue swelling, osteopenia, and erosions; while an ultrasound may show synovial hyperemia.
Finally, synovial fluid analysis typically reveals inflammatory synovial fluid with a white blood cell count between 2000 to 10,000 cells per millimeter cubed, with negative gram stain, cultures, and crystal analysis.
Synovial fluid analysis is important because it can help rule out other conditions, such as septic arthritis, which will have a very high WBC count and may demonstrate bacteria on cultures; or gout, which will have crystals present in the synovial fluid!Alright, now moving on to management.

Treatment5:55–6:50

Early treatment with a disease-modifying antirheumatic drug, or DMARD, is recommended. The most common DMARD used is methotrexate, with or without a short course of glucocorticosteroids, in combination with occupational and physical therapy.
Keep in mind that you must screen for hepatitis B and C before starting a DMARD. Now, here’s another clinical pearl to remember!
DMARDs, like methotrexate, may take weeks to months to achieve optimal effects, while NSAIDs and systemic and intraarticular glucocorticoids can act rapidly to reduce disease activity.
However, systemic glucocorticoids should only be used to treat rheumatoid arthritis when absolutely necessary, since they can have several severe side effects, including the risk of gastrointestinal bleeding and hyperglycemia.

Assess the response6:50–7:49

Once you initiate the management, you should wait 3 months and assess the patient’s response to treatment. If the response is adequate and your patient is improving, continue the current therapy.
However, if it is inadequate and the inflammation persists, add a biologic agent. The most commonly used first-line biologic in rheumatoid arthritis is a TNF inhibitor, such as etanercept or adalimumab.
You can also consider adding a short-term course of systemic glucocorticosteroids, if it was not already part of the initial treatment regimen, but again remember to balance that decision against the risk of side effects.
Here’s a clinical pearl! Before you start your patient on a TNF inhibitor, be sure to screen them for tuberculosis and hepatitis B and C, as TNF inhibitors can cause reactivation of these conditions.
Also, TNF inhibitors are contraindicated in patients with moderate to severe heart failure as they can cause worsening of the heart failure.

Review7:49–8:45

Alright, as a quick recap… Rheumatoid arthritis is a chronic, autoimmune disorder targeting the synovial joints, leading to cartilage destruction and impaired function.
Diagnosis is based on clinical findings, including at least 6 weeks of symmetrical joint stiffness lasting more than 30 minutes and joint swelling.
Your exam will also demonstrate symmetrical small joint swelling and tenderness. These findings are enough to make the diagnosis of rheumatoid arthritis, but you may want labs and imaging to help you determine the patient’s prognosis.
The initial treatment primarily involves a DMARD like methotrexate, but in severe cases, you should consider a short course of glucocorticosteroids as well.
Also, don’t forget to refer your patient to occupational and physical therapists. In some cases, you may also need to consider addition of a biologic with or without a short course of