2Definition Inflammatory arthritis associated with psoriasis Usually seronegative for Rheumatoid FactorClassified with HLA-B27-associated spondyloarthropathies
3EpidemiologyLikely in up to 25-34% of patients with presence of skin diseaseOverall prevalence %M=F although it differs in subsetsPeak age of onset between years
4CASPAR criteria evidence of psoriasis current - 2 history of - 1 family history of - 1psoriatic nail dystrophy (onycholysis, pitting, hyperkeratosis)negative rheumatoid factordactylitis, either current or history ofradiological evidence of juxta-articular new bone formationCASPAR = Classification of Psoriatic Arthritisbased on study of 588 pts with PsA, 536 pts with other inflammatory arthritisOnce 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%.
5Subtypes DIP joint pattern oligoarticular (<5 joints) pattern, usually assymetricpolyarticular (>=5 joints), symmetric in halfarthritis mutilansspondyloarthritisPatterns 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.
6Other Rheum Findingsenthesitis (inflammation at site of tendon insertion)tenosynovitis (inflammation of tendon and its enveloping sheath)dactylitis or “sausage digit”
7Extra-articular findings skin - psoriasisnails - pits and onycholysispitting edema - often asymmetricalocular inflammation - conjunctivitis, iritisarticular disease can develop before skin changes in ~15% of adults, ~15% concomitantly, ~70% skin firstpits = sharply defined depressions in the plate usually occuring in large numbers and involving several nailsonycholysis = 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
8How to diagnose those without skin findings look for distal joint involvement in asymmetric distributionlook at the nailslook in earsask about family historydactylitisnail lesions are present in 80-90% of those with PsA, 46% of those with psoriasis uncomplicated by arthritis
10Diagnostic Testing no diagnostic laboratory testing radiologically: erosive changes and new bone formation in distal jointslysis of terminal phalangesfluffy periostitis and new bone formation at sites of enthesitis“pencil in cup” appearancecan have elevated ESR and leukocytosis in 1/3 from inflammatory responsecan see anemia from AoCDRhF positive in 2-10%, ANA low titer in ~1/2, clinically significant titers ~14%, anti-dsDNA 3%, anti-CCP in 8-16%
11Differential Reactive (Reiter’s) Arthritis Rheumatoid Arthritis with concomitant psoriasisankylosing spondylitisgouty arthritisreactive - lack of preceding infectious episode, absence of genitourinary involvementrheumatoid - involvement of DIPs, asymmetry, spondyloarthropathy, dactylitis, skin and nail findings, radiologicankylosing spondylitis - radiography, more frequent involvement of cervical spine & less of lumbar spine, asymmetric sacroiliitis, skin and nail findings
12Treatment 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.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)
13Course and Prognosis20% of patients have a severe an debilitating form of arthritisoriginally thought to be more benign course than RhAprogression of clinical damage occurs in a majority of patientsradiologic changes occur over time despite treatmentpresence of >=5 swollen joints + high medication level were predictors for progression of clinical damagelow ESR protective.HLA B22 protective, but others (HLA-B27, HLA-DR7, HLA-B39, HLA-DQw3 in absence of HLA-DR7) predict progression
14ReferencesKlippel, John. Primer on the Rheumatic Diseases. Edition 12. Atlanta, GA: Arthritis Foundation; 2001:Gladman, Dafna. Psoriatic arthritis. Dermatologic Therapy. Vol ,