Summary Psoriatic Arthritis is a seronegative spondyloarthropathy that presents with DIP predominant arthritis of the hands, rash with silvery plaques, uveitis, and dysmorphic nails. Diagnosis is made based on a thorough evaluation of serum labs, clinical features, and radiographic findings. Treatment is usually medical management with a variety of options including corticosteroids, disease modifying anti-rheumatic drugs, and biological drugs. Epidemiology Incidence affect up to 5-20% of patients with psoriasis Demographics equally affects men and women Etiology Pathophysiology 5 patterns of arthritis asymmetric oligo/monoarticular arthritis affecting DIPJ, PIPJ, MCPJ DIP-predominant arthritis arthritis mutilans symmetric, RF-negative polyarthritis psoriatic spondyloarthropathy Genetics HLAB27 found in 50% Presentation Symptoms arthritic symptoms in hands Physical exam rash with silvery plaques over extensor surfaces (elbows, knees) typically precede joint involvement by several years (80-85% of time) hands dactylitis (sausage digit) onychodystrophy (nail pitting) onycholysis (lifting of nail plate starting distally) arthritis mutilans opera glass hands (la main en lorgnette) excess skin from the shortening of the phalanx bones becomes folded transversely, as if retracted into one another like opera glasses chronic uveitis entheses such as achilles tendonitis, posterior tibial tendonitis, and plantar fasciitis Imaging Radiographs hands distal phalanx acrolysis DIP arthritis classic finding is "pencil-in-cup" deformity simultaneous destruction of the head of the middle phalanx and expansion of the base of the distal phalanx different than DJD by presence of centripetal erosions which cause joint space widening small joint erosions or fusions (PIP, MCP, and wrist commonly involved) fluffy periostitis (caused by periosteal ossification) acroosteolysis (resorption of the distal phalanx tuft) flail digits spine in axial disease sacroiliitis syndesmophytes paravertebral ossification destructive discovertebral lesions Studies HLAB27 found in 50% RA and ANA tests are usually negative Treatment Nonoperative NSAIDS, methotrexate, sulfasalazine, cyclosporine,TNF-alpha inhibitors indications mainstay of treatment similar to RA Operative digit fusion vs resection arthroplasty indications advanced joint disease