THU0455 Evaluating Psoriatic Skin Lesions in Psoriasis and Psoriatic Arthritis: Ultrasound as A Complementary Measure

Background Currently, the diagnosis and assessment of psoriatic arthritis (PsA) and psoriasis (PsO) skin lesions are mostly done by visual inspections, and when in doubt, supplemented by biopsies. Although PsA is primarily assessed by physical examination, the utility of ultrasound (US) is beneficial. Objectives The aim of this proof of concept study was to determine the performance of ultrasound (using advanced imaging software applications) in assessing skin lesions and inflammation in selected PsA and PsO patients. Methods A rheumatologist and dermatologist assessed the PsA and PsO patients respectively. PsA examination included the standard clinical joint assessments, and we thereafter evaluated the hands & wrists and symptomatic joints with US for synovitis & tenosynovitis (including nail beds & tendons). Blinded by the clinical results and treatment plans, the epidermal, dermal and subcutaneous tissue thicknesses of 2 of the most affected psoriasis lesions were US scanned using high frequency B-Mode, automated Color Doppler quantification (CDQ; measured over 4 seconds) and elastography applications (measuring lesion size, depth, hyperemia and tissue elasticity). The skin tissue adjacent to the psoriasis lesions, as well as the unaffected skin on the contralateral side (self-control) was measured. Results A total of 270 skin depth measurements (2 of the most affected lesions, 3 intervals apart, at 3 different sites described above) of 5 PsA/PsO patients were analyzed. Epidermal thickness differed significantly between the adjacent and control tissue layers [F (2,27) =30.95, MSE =0.76, p Conclusions Ultrasound metrics of skin tissue (plaque characteristics, tissue depth & elasticity, and Doppler activity quantification) has potential as a complementary measure for the clinical assessment of PsA and PsO. Disclosure of Interest None declared