Rheumatoid Arthritis Flashcards
What is RA
- Chronic, symmetric, systemic disease that primarily targets the synovium
- May have extra-articular manifestations
*can present in a variety of ways
Complicaitons of RA
- Leads to synovial inflammation and proliferation
- Loss of articular cartilage seen on xray
- Erosion of juxta-articular bone/osteopenia
- Tendon and ligament destruction
*usually triggered by something to cause the autoimmune response
Who does RA effect?
- Affects 1% of the adult population
- Females: Males (3:1)
- Can present in any age
- Women: Most commonly in late childbearing years
- Men: 50-80 years of age
What is the etiology of RA
*Etiology is unclear–environmental, genetic, or infectious
- Likely due to an unknown antigen(s) that trigger the response in a genetically susceptible patient
- Genetic susceptibility – 30 loci currently identified (HLA-DRB1 strongest)
- Antigens – viruses (Parvovirus*, EBV)
- Smoking or periodontal inflammation –> associated with anti-CCP
Synovial-based disease
RA
Describe the pathophysiology of RA
- Unknown antigen activates/injures synovial microvascular endothelial cells
- Synovial inflammation and hypertrophy: CD4+ T cells, macrophages, B cells, and plasma cells
- Release of inflammatory cytokines by synovial macrophages: IL-1, TNF-alpha*, IL-6**
- Cytokines induce fibroblasts and chondrocytes to produce PGE2, collagenase, and proteinases resulting in cartilage and bone destruction
Presentation of RA
- Insidious onset over weeks to months (if <6 weeks think of reactive arthritis, gout, or pseudogout)
- Symmetric Joint Involvement
- Small joints first – MCPs, PIPs, MTPs (DOES NOT INVOLVE DIPs)
- Then wrists, knees, elbows, ankles, hips and shoulders
- Pain and swelling
- Stiffness -Morning stiffness for at least 1 hour; gel phenomenon–> improves with activity**
Others: - Fatigue
- Low grade fever
- Wt. loss
- poor sleep
- Dry eyes/mouth
- affects on ADLs
Why are occiptal HA a problem/concern in RA
C1-C2 subluxation – erosion of the odontoid
Brainstem impingement
axis and atlas can erode and protude to the –> get Xray of C-spine to look for suplaxation)
What is the primary care screening tool for RA
- Significant discomfort with squeezing the MCP and MTP joints (Positive Squeeze test)
- Presence of 3 or more swollen joints
- More than 1 hour of morning stiffness
Signs of RA on PE
- assess joints for: (tender, synovitis, erythema, warmth) ((typically warm but not red))
- Deformities/ ulnar deviation that is not correctable
- Crepitus
- Decrease ROM
- Tenosynovitis (can be in any tendor- extensor or volar aspect of arms)
- Nodules -By areas w/ pressure (elbows)
What joints are often involved in RA?
- Small joints first – MCPs, PIPs, MTPs
- Then wrists, knees, elbows, ankles, hips and shoulders
- C-spine
- Spine
- Shoulder
- Elbow
RA in the spine puts you at risk for:
Compression fracture due to osteoporosis
RA in the elbow puts you at risk for:
- Bursitis
- Nerve entrapment due to synovitis
- nodules
**numbness in 4th and 5th digit–> ulnar nerve entrapment
Describe hand/wrist manifestations of RA
- Nodules,
- synovitis,
- ulnar deviation,
- swan neck deformities,
- subluxation
- Tenosynovitis leading to:
- triggering,
- nerve entrapment, or
- tendon rupture
describe complications of RA in the hip and knee
Hip:
- Bursitis
- Avascular necrosis of the femoral head due to GCs
Knee:
-synovial cyst/baker cyst
describe complications of RA in the ankles and foot
- Synovitis,
- cock-up toe deformities,
- hallux valgus,
- pes planus-> leads to plantar fasciitis ,
- tarsal tunnel (tingling in feet)
What labs should you order with RA
- CBC (normocytic anemia, elevated platelets)
- ESR (chronic) and CRP (acute)
- +/- Synovial fluid
- Anti-CCP
- RF
- HepC
* *Do not order an ANA (ONLY GET ANA TO confirm suspicion for SLE)
* *Do not need positive labs to confirm dx if hx and PE are suggestive
Describe the use of synovial fluid analysis in RA
- Not pathognomonic for RA
- Inflammatory with two-thirds WBC being neutrophils
- (do for gout, pseudogout, septic)
Describe the use of RF for RA
Only + in 50%-70%
Not unique to RA
If + correlates with more severe disease
Describe the use of anti-CCP for RA
- Confirmatory test for RF
- Present in 60-70%
- 90-98% specific for RA
- Correlate strongly with more aggressive/ erosive disease
- Can be present years before the diagnosis of RA
Describe common hand XRAY findings of RA
- Erosive/fused joints
- Pencil and cup deformity– eroding down into metacarpal
- bone remodeling/stepping off
- DIPs are normal
- Osteopenia near joint
What is the ACR diagnostic criteria for RA
Score >6
1. Joint involvement: (1 large joint=0, 2-10 large=1, 1-3 small=2, 4-10 small w/ or w/o large=3, >10 joints (at least 1 small)=5
- serology (-RF and antiCCP=0, low+ RF and antiCCP= 2, high+ RF and antiCCP=3)
- Acute phase reactants (normal CRP and ESR=0, or 1 if either abnormal)
- duration: (<6 weeks= 0, >6 weeks=1)
What are considered small and large joints?
Small joints: MCP, PIP, wrists
Large joints: everything else (hip, shoulder, knee)
What are poor prognosis factors?
- Functional limitations (ie. hand deformities)
- RF + or Anti-CCP +
- Erosions on x-rays
- Extra-articular disease
- Interstitial lung disease, vasculitis, scleritis, rheumatoid nodules
**escalate their treatment quicker