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
Ankylosing spondylitis
- Pattern of joint involvement
- Extra articular features
- Diagnostic studies
- Sacroiliac & spinal involvement; symmetric; large joints (shoulders, hips); spares small joints
- uveitis
- calcification of anterior longitudinal ligament of spine on radiograph; sacroiliitis; usually HLA-B27 +
Psoriatic arthritis
- Pattern of joint involvement
- Extra articular features
- Diagnostic studies
- asymmetric oligoarthritis or symmetric polyarthritis; DIP joint preference; dactylitis (sausage digits); enthesitis (insertion of tendon to bone); axial disease with sacroiliitis
- psoriasis, uveitis
- “Pencil in cup” deformities; erosions and osteophytes on radiograph; sometimes HLA B27 +
Reactive arthritis
- Pattern of joint involvement
- Extra articular features
- Diagnostic studies
- asymmetric oligoarthritis; knee and ankle involvement; enthesitis; Achilles tendinitis; plantar fasciitis; sacroiliitis
- uveitis; keratoderma blennorrhagicum; preceding infection (Chlamydia; enteropathic)
- sacroiliitis; sometimes HLA B27 +
Inflammatory bowel disease associated arthritis
- Pattern of joint involvement
- Extra articular features
- Diagnostic studies
- asymmetric; sacroiliitis; knee and feet involvement
- Crohn disease; ulcerative colitis
- sacroiliitis; sometimes HLA B27 +
Anti-smooth muscle ab
autoimmune hepatitis
Which ANA sub-serologies are appropriate to test for if ANA is negative? What disorders are they associated with?
anti-SSA - SLE
anti-Jo-1 - polymyositis
Skin findings: Butterfly (malar) rash; photosensitive rash; discoid lupus erythematosus; subacute cutaneous lupus erythematosus; oral ulcerations, usually painless; alopecia; lupus panniculitis
Systemic lupus erythematosus
Skin findings: Gottron papules (erythematous plaques on extensor surfaces of MCP, PIPs); photodistributed poikiloderma (esp shawl sign over the back and shoulders and V sign over posterior neck/back or neck/upper chest); heliotrope rash (violaceous rash on the upper eyelid); mechanic’s hands; nailfold capillary abnormalities; holster sign (poikilodermic rash along lateral thigh)
Dermatomyositis
Skin findings: skin findings of dermatomyositis but without myositis findings
amyopathic dermatomyositis
Skin findings: Skin thickening and hardening
- limited disease: involves face and skin distal to elbows/knees
- diffuse disease: involves skin proximal to distal forearms/knees
Nailfold capillary changes
Systemic sclerosis
Skin findings: palpable purpura, cutaneous nodules, ulcers
Vasculitis
Skin findings: Painful oral and genital ulcers; erythema nodosum; acne/folliculitis; pathergy
Behcet syndrome
Skin findings: Erythema nodosum
Sarcoidosis
Skin findings: Plaque psoriasis on extensor surfaces, umbilicus, gluteal fold, scalp and behind ears; pustular psoriasis on palms and soles; arthritis may proceed rash by up to 10 years; nail pitting; onycholysis
Psoriatic arthritis
Skin findings: keratoderma blennorrhagicum (rash on soles, toes, palms); circinate balanitis (rash on penis)
Reactive arthritis
Skin findings: Evanescent, salmon colored rash on truck and proximal extremities
Adult onset Still disease
Skin findings: Erythema marginatum (annular pink to red nonpruritic rash with central clearing)
Rheumatic fever
Skin findings: erythema chronicum migrans (slowly expanding, often annual lesion with central clearing)
Lyme disease
What are the estimates for maximal expected normal ESR based on age and gender?
Men = age/2 Women = (age +10)/2
What is CRP? How does it rise and fall during illness?
C-reactive protein is an acute phase reactant synthesized by the liver during inflammation. It rises and falls more quickly than ESR during inflammation.
What are complement levels and how are they used in monitoring rheumatologic disease?
Complement levels are generally increased in inflammatory states, that is they are acute phase reactants. But when immune complexes are present like in SLE or types of vasculitis, complement is consumed.
What is CH50?
measures the ability of serum complement to lyse immunoglobulin coated erythrocytes. Assesses overall activation of the classical complement pathway and is abnormal when any component is depleted.
What is RF and ANA?
RF is an immunoglobulin directed against the Fc portion of IgG. ANA is directed against nuclear antigens.
What is considered a low vs high ANA titer?
Low-titer (1:40) High titer (1:160)
Radiographic findings: RA
Boney erosions; periarticular osteopenia; subluxations; sot tissue swelling; MCP and PIP involvement on hand radiograph
Radiographic findings: Osteoarthritis
Asymmetric joint space narrowing; osteophytes; subchondral sclerosis and cystic changes; DDD with collapse of disks; facet joint osteophytes; spondylolisthesis and kyphosis
Radiographic findings: DISH
Calcification of the anterior longitudinal ligament; bridging horizontal syndesmophytes; usually R>L
Radiographic findings: AS
Sacroiliitis; squaring of the vertebral bodies; bridging vertical enthesophytes; shiny corners
Radiographic findings: Psoriatic arthritis
Destructive arthritis with erosions and osteophytes; DIP involvement; pencil in cup and arthritis mutilans on hand radiographs
Radiographic findings: Gout
Punched out erosions with sclerotic border and overhanging edge; periarticular soft tissue swelling with calcifications in tophaceous deposits
Radiographic findings: Calcium pyrophosphate deposition
Chondrocalcinosis, most commonly of the knees, shoulders, wrists, pubic symphysis, leads to osteoarthritis
What rheumatologic condition is more detectable on CT/
Calcium pyrophosphate deposition; more sensitive in detecting bone erosions
Name the leukocyte ranges for normal, noninflammatory conditions and inflammatory states in synovial fluid.
Normal < 200 uL
Noninflammatory 200 - 2,000 uL
Inflammatory > 2,000 uL
