Diagnosis and Management of Psoriatic Arthritis

Diagnostic Criteria and Assessment

The diagnosis of psoriatic arthritis (PsA) should follow the CASPAR criteria, with a comprehensive evaluation including joint assessment, laboratory tests, and imaging to identify inflammatory musculoskeletal disease, as recommended by the American College of Rheumatology 1, 2, 3
Diagnosis should ideally involve both dermatology and rheumatology expertise to confirm psoriasis and inflammatory musculoskeletal disease respectively, according to the American Academy of Dermatology 1, 3
CASPAR criteria are the standard for diagnosis, focusing on inflammation features including joint pain, spine/enthesis involvement with erythema, warmth, swelling, and prominent morning stiffness, as stated by the European League Against Rheumatism 1, 2, 3

Baseline evaluation of PsA should include peripheral joint assessment, examining 68 joints for tenderness and 66 joints for swelling, as recommended by the American College of Rheumatology 1, 2, 4
Pain evaluation should be done using patient-reported assessment with visual analogue or category rating scales, according to the American Academy of Dermatology 1, 3
Patient global assessment of disease activity should be measured, as stated by the European League Against Rheumatism 1, 2
Physical function should be measured using validated tools such as the Health Assessment Questionnaire (HAQ), as recommended by the American College of Rheumatology 1, 3
Health-related quality of life should be assessed using general (SF-36) or PsA-specific measures (PsAQoL), according to the American Academy of Dermatology 1, 2
Fatigue assessment should be done through patient self-report or instruments like FACIT, as stated by the European League Against Rheumatism 1, 3
Laboratory tests, including acute phase reactants (CRP, ESR), should be performed, as recommended by the American College of Rheumatology 1, 2, 4
Radiographic assessment should be based on clinical manifestations and physician judgment, according to the American Academy of Dermatology 1, 3

Dactylitis ("sausage digit") is a combination of enthesitis and synovitis involving an entire digit, as described by the Journal of the American Academy of Dermatology 5
Enthesitis is inflammation at tendon, ligament, or joint capsule insertion sites, commonly at plantar fascia and Achilles tendon, according to the Journal of the American Academy of Dermatology 5
Nail disease is commonly associated with PsA, especially with DIP joint involvement, as stated by the Journal of the American Academy of Dermatology 5

Laboratory tests, including ESR and CRP, should be used to assess inflammation, and rheumatoid factor is typically negative (seronegative arthritis), as recommended by the American College of Rheumatology 1, 5

Polyarticular disease (high number of actively inflamed joints) is a factor associated with poor prognosis and progressive joint damage, as stated by the American College of Rheumatology 1, 3
Elevated ESR is a factor associated with poor prognosis and progressive joint damage, according to the American Academy of Dermatology 1, 2
Previous treatment failures are a factor associated with poor prognosis and progressive joint damage, as recommended by the European League Against Rheumatism 1, 3
Existing joint damage (clinical or radiographic) is a factor associated with poor prognosis and progressive joint damage, according to the American College of Rheumatology 1, 2
Diminished quality of life, as measured by standardized tools, is a factor associated with poor prognosis and progressive joint damage, as stated by the American Academy of Dermatology 1, 3

Cardiovascular disease risk factors (hypertension, hyperlipidemia, diabetes) should be evaluated, as recommended by the Journal of the American Academy of Dermatology 5
Metabolic syndrome components should be evaluated, according to the Nature Reviews Rheumatology 5, 6
Inflammatory bowel disease should be evaluated, as stated by the Journal of the American Academy of Dermatology 5, 7
Depression and anxiety should be evaluated, according to the Nature Reviews Rheumatology 6
Liver disease (non-alcoholic fatty liver disease) should be evaluated, as recommended by the Nature Reviews Rheumatology 6

Treatment response for peripheral arthritis can be evaluated using criteria developed for rheumatoid arthritis, such as the 28-joint Disease Activity Score (DAS28) and European League Against Rheumatism (EULAR) response criteria, as stated by the American College of Rheumatology 1, 4
For axial disease, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) may be used to measure disease activity and treatment response, according to the European League Against Rheumatism 3, 4