4/18 SNSA - Corbett Flashcards
summary table of SNSAs
seronegative spondyloarthropathies
break down terms
involved dieases
MSK features
genetic features
seronegative = NO rheumatoid factor
spondyloarthropathies = disease of SI joints and/or spine
four SYSTEMIC infl joint disorders (PAIR)
- Psoriatic arthritis
- Ankylosing spondylitis
- Infl Bowel Disease-associated spondyloarthropathy
- Reactive arthritis (aka Reiter’s syndrome)
*undifferentiated spondyloarthropathy
uniting clinical/radiographic/genetic features
-
MSK features
- infl of axial skeleton (spine and SI disease)
- asymmetrical oligoarthritis
- infl of four or fewer periph joints
- marked extrasynovial infl
- enthesis (sites of insertion of ligs/tends) + jt capsule, periosteum, cartilage, subchondral
- dactylitis
-
genetic features
- HLA-B27 predisposition (esp in ankylosing spondylitis)
- extra-axial conds: ocular (uveitis), GI (IBD), GU, cardiac (aortitis, valvular insuff, heart block), cutaneous (keratoderma blennorhagicum)
SNSA features: MSK fts
infl of axial skeleton
sx of “infl back pain”
- tenderness of SI joints by direct or indirect pressure
- limited spinal ROM (Schober test)
- deformity
- loss of lumbar lordosis
- accentuated thoracic kyphosis
- resolution of inflammation occurs by FIBROSIS
- periarticular osteitis and periostitis can result in bony syndesmophytes (bridge adj vertebral bodies, protrude at sites of lig attachment) → fusion of joint
- new bone laid down instead of old bone eroded
- “bamboo spine”
SNSA features: MSK fts
oligoarthritis
oligo = 2-4 joints involved!
- mono: 1: septic arthritis, crystal arthropathy
-
oligo: 2-4: SNSAs
- typically involves lower extremities
- poly: 4+: RA
SNSA features: MSK features
extrasynovial infl
infl outside of joint space
enthesitis: infl at fibrous points where ligs and tendons attach
- erosion and osteitis
- ossification
- periosteal new bone formation
*mostly lower extremities, but also axial spine (ex. Achilles)
RA vs enthesitis of SNSA
RA: target is where the capsule is inserting onto bone
- osteoclasts consume the bone → erosion
SNSA enthesitis: target is outside bone space
- bone loss, but new bone made quickly
dactylitis
“sausage digit”
most commonly assoc with psoriatic arthritis (all assoc with the other SNSAs)
flexor synovitis due to infl of tendon sheath
skin lesions
ocular involvement
cardiac involvement
treatment
- relief of sx
- aggressive strategy of disease mod: slow or stop disease progression, maintain/preserve fx
- support patients/help cope
ankylosing spondylitis
most common SA
“immobility and consolidation”
“infl of vertebrae”
1. axial skeleton (SI joints, spine)
2. male predominance (3-9x; white males 15-40yo)
- 90% HLA B27 (5-6%)
dx often delayed
when think ankylosing spondylitis?
red flags
- age under 40
- chronicity (insidious onset for longer than 3mo)
- infl back pain
- sx worse in AM, inactivity → improve with exercise (not rest)
when think mechanical process?
red flags
- increasing age at onset
- chronicity: acute onset (ex. while lifting), or chronic w/ OA
- “mechanical”-type pain (radicular radiation, sx worse with activity)
Schober test
assessment of spine mobility
key clinical features of ankylosing spondylitis
(systemic)
what would you NOT expect?
enthesitis
peripheral arthritis
anterior uveitis
DONT EXPECT dactylitis (more common in psoriatic arthritis)
key radiologic features of ankylosing spondylitis
treatment of ankylosing spondylitis
- NSAIDs (sx relief)
- sulfasalazine (for peripheral jt disease - not effective for spondylitis)
- TNFalpha antagonist
- adalimumab
- etanercept
- infliximab
AS summary
reactive arthritis
etiology
associated HLA
triad
inflammatory arthritis triggered by infectious agent outside joint
- oculogenital: Chlamydia
- enteric: Shigella, Salmonella, Campylobacter, Yersinia
- facultative intracellular pathogens
**arthritis is self perpetuating → NOT responsive to antibiotics!
- present 1-4wk after infectious event with asymmetric arthritis (LE oligoarth), enthesitis, dactylitis, sacroiliitis, spondylitis
TNF secretion is key to pathogenesis → acts as infl mediator in synovium, enthesis, and bone
- potentiates bone resorption by clasts
associated with HLA B27 (80% with ReA)
subset have triad: urethritis, uveitis, arthritis
- “can’t see, can’t pee, can’t climb a tree”
ReA
non-articular features
ReA treatment
most pts: ReA resolves in 4-6mo
30% recurrent/chronic sx
- NSAIDs
- sulfasalazine/MTX
- TNFalpha antagonist
ReA key points/summary
psoriatic arthritis
20-30% of pts with psoriasis
HLA B27 and HLA Cw
pathophys
- T cell mediated
- TNF is an imp target
peripheral jt disease (95%)
- small joint polyarth
- asymmetrical oligoarthritis of LE
- dactylitis
- DIP arthropathy + nail pitting
- erosive arthritis
Psoriatic arthritis vs RA?
arthritis mutilans
5% of psoriatic arthritis
v severe
due to bone remodeling
“pencil in cup deformity”
psoriatic arthritis key points/summary
IBD-assoc spondyloarthropathy
HLA B27 assoc
20% of pt with IBD (more common w Crohn’s than UC)
asymmetric LE arthritis that tracks with GI disease
abrupt onset (type1)
treatment of IBD spondyloarthropathy
- NSAIDs
- sulfasalazine/MTX
- TNFalpha antags
