2. Definition
Inflammatory arthritis associated with psoriasis
Usually seronegative for Rheumatoid Factor
and cyclic citrullinated peptides (CCP)
Classified with HLA-B27-associated
spondyloarthropathies
3. Epidemiology
Likely in up to 25-34% of patients with
presence of skin disease
Overall prevalence 0.04-1.2%
M=F although it differs in subsets
Peak age of onset between 30-55 years
4. CASPAR criteria
evidence of psoriasis
current - 2
history of - 1
family history of - 1
psoriatic nail dystrophy (onycholysis, pitting,
hyperkeratosis)
negative rheumatoid factor
dactylitis, either current or history of
radiological evidence of juxta-articular new
bone formation
6. Other Rheum Findings
enthesitis (inflammation at site of tendon
insertion)
tenosynovitis (inflammation of tendon and its
enveloping sheath)
dactylitis or “sausage digit”
7. Extra-articular findings
skin - psoriasis
nails - pits and onycholysis
pitting edema - often asymmetrical
ocular inflammation - conjunctivitis, iritis
8. look for distal joint involvement in asymmetric
distribution
look at the nails
look in ears
ask about family history
dactylitis
How to diagnose those
without skin findings
10. Diagnostic Testing
no diagnostic laboratory testing
radiologically:
erosive changes and new bone formation in
distal joints
lysis of terminal phalanges
fluffy periostitis and new bone formation at
sites of enthesitis
“pencil in cup” appearance
12. Treatment
NSAIDs if disease is mild.
PT, OT, splinting devices
If erosive disease, treat aggressively with
DMARDs (MTX, Sulfasalazine, CsA).
If skin disease is the major issue, should be
managed by a dermatologist.
Early referral to rheumatology for initiation of
DMARDs to prevent progression.
13. Course and Prognosis
20% of patients have a severe an debilitating
form of arthritis
originally thought to be more benign course
than RhA
progression of clinical damage occurs in a
majority of patients
radiologic changes occur over time despite
treatment
Notes de l'éditeur
CASPAR = Classification of Psoriatic Arthritis
based on study of 588 pts with PsA, 536 pts with other inflammatory arthritis
Once presence of MSK inflammatory condition is established, if they score three + points, can be classified as PsA with sensitivity 91.4%, specificity of 98.7%.
Patterns of involvement may be helpful early in course of disease, but over time the pattern often changes. But it is useful as a predictor of prognosis.
Distal and arthritis mutilans are most specific for PsA but not most common.
Polyarthritis is most common, followed by oligoarthritis.
articular disease can develop before skin changes in ~15% of adults, ~15% concomitantly, ~70% skin first
pits = sharply defined depressions in the plate usually occuring in large numbers and involving several nails
onycholysis = separation of nail from its bed (sometimes need to distinguish from fungal infection)
while skin dz does not necessarily correlate with joint disease, nail involvement does seem to correlate more
.
nonpitting edema from chronic lymphedema is a rare extra-articular finding
nail lesions are present in 80-90% of those with PsA, 46% of those with psoriasis uncomplicated by arthritis
can have elevated ESR and leukocytosis in 1/3 from inflammatory response
can see anemia from AoCD
RhF positive in 2-10%, ANA low titer in ~1/2, clinically significant titers ~14%, anti-dsDNA 3%, anti-CCP in 8-16%
reactive - lack of preceding infectious episode, absence of genitourinary involvement
rheumatoid - involvement of DIPs, asymmetry, spondyloarthropathy, dactylitis, skin and nail findings, radiologic
ankylosing spondylitis - radiography, more frequent involvement of cervical spine & less of lumbar spine, asymmetric sacroiliitis, skin and nail findings
Only two RCTs of MTX in PsA and the evidence is not overwhelming in terms of efficacy of MTX.
Sulfasalazine involved in 6 RCTs with only modest effect.
CsA effective for both skin and joint manifestations, but not well tolerated.
Other DMARDs = azathioprine, gold, antimalarials, anti-TNF agents (etanercept, infliximab, adalimumab, golimumab), and newer T-cell directed agents not yet approved for PsA (although approved for psoriasis)
presence of >=5 swollen joints + high medication level were predictors for progression of clinical damage
low ESR protective.
HLA B22 protective, but others (HLA-B27, HLA-DR7, HLA-B39, HLA-DQw3 in absence of HLA-DR7) predict progression