MKSAP 1: Approach to the Patient Flashcards
Distinguish characteristics of inflammatory vs noninflammatory pain.
Inflammatory: erythema, warmth, soft tissue swelling. >60 min morning stiffness. +fever, fatigue, malaise, WBC count > 2K. Elevated ESR, CRP. Imaging: symmetric diffuse joint space narrowing, periarticular osteopenia, erosions, bony proliferation
Non-inflammatory: no soft tissue swelling, minimal or no warmth, <30 min morning stiffness, absent constitutional symptoms. WBC 200 - 2000. Inflammatory markers usually low. Imaging: asymmetric, compartmental joint space narrowing; osteophytes; subchondral sclerosis
Differentials for inflammatory vs noninflammatory monoarthritis and what is the best first step in evaluation?
Inflamm monoarthritis: infection, bacteria (ACUTE) vs atypical organisms - fungi, mycobacteria, spirochetes (Lyme) (CHRONIC)
Noninfectious inflammatory monoarthritis: crystal related, usually acute but can be chronic in calcium pyrophosphate deposition; autoimmune
Noninflammatory monoarthritis: osteoarthritis or mechanical derangement (torn meniscus or ligament)
Aspiration; analysis of synovial fluid. Gram stain with culture and crystals
Differential for oligoarthritis
Oligoarthritis involves 2-4 joints and often asymmetric. Most common are the spondyloarthritis diseases - AS, psoriatic arthritis, reactive arthritis, inflammatory bowel disease associated arthritis.
Also disseminated gonococcal infection, rheumatic fever, and Lyme disease.
Also possible to have osteoarthritis present this way.
Differential for polyarthritis
Five or more joints. Rheumatoid arthritis, SLE, and psoriatic arthritis. Common to have viral infections such as hepatitis, parvovirus, rubella, herpes, HIV, adenovirus, mumps, or enterovirus.
Differential also includes drug induced serum sickness, an immune complex reaction to bacterial infections such as endocarditis or other forms of crystal or autoimmune diseases
ANA
SLE
Also SSc, Sjogren, and MCTD
does not correlate with disease activity
Anti DS DNA
SLE; correlates with disease activity, especially kidney disease
Anti smith
SLE; most specific for SLE but does not correlate with disease activity
Anti U1 RNP
MCTD**
SLE
Anti SSA - anti-Ro
Anti SSB - anti-La
Anti-SSB: Sjogren syndrome (sicca syndrome); neonatal lupus
Anti-SSA: Sjogren syndrome; neonatal heart block, subacute cutaneous lupus
Sjogren
SLE
RA
SSc
Anti Scl 70 (antitopoisomerase)
DcSSc
SSc
Pulmonary fibrosis
Anticentromere pattern of ANA
LcSSc (CREST)
SSc and PH
c-ANCA
(anti-pr3)
GPA
p-ANCA
(anti-MPO)
MPA; EPGA
Anti-Jo 1
Polymyositis & antisynthetase syndrome
Rheumatoid factor
RA; Sjogren
Cryoglobinemia
Anti-CCP
RA
Anti-histone
DILE
Cryoglobulins
Vasculitis; hepatitis C; myeloma; SLE; RA
What does blood in the synovial fluid indicate?
Typically trauma but can also be related to hemophilia
Rheumatoid arthritis
- Pattern of joint involvement
- Extra articular features
- Diagnostic studies
- symmetric polyarthritis; involves small joints (MCP, PIP, MTP) but also can involve hips, knees, elbows, shoulders & c-spine; spares thoracic and L-spine and DIP joints
- Rheumatoid nodules; dry eyes & mouth; interstitial lung disease; Felty syndrome (splenomegaly, leukopenia, leg ulcers)
- RF; anti-CCP; acute phase reactants; erosive changes on radiograph
SLE
- Pattern of joint involvement
- Extra articular features
- Diagnostic studies
- Symmetric polyarthritis with large & small joint involvement; minimal to no swelling
- Constitutional (fever, fatigue), multi-organ involvement (rash, oral ulcers, alopecia, serositis, kidney disease, neurologic disease, cytopenias)
- ANA; anti-DS DNA ab; anti-Smith; anti-U1-RNP; anti-SSA; anti-SSB; no erosions on radiograph