Detection of subclinical skin manifestation in patients with psoriasis and psoriatic arthritis by fluorescence optical imaging

Abstract

Objectives: To investigate the frequency of subclinical skin inflammation in both hands by fluorescence optical imaging (FOI) in patients with psoriasis/psoriatic arthritis (Pso/PsA) vs. rheumatoid arthritis (RA) and healthy individuals, and to correlate these findings with cardiovascular (CV) risk factors. Patients and methods: The FOI scans were analyzed retrospectively to detect clinically invisible skin enhancement (0-3 scale) in both hands without relationship to underlying joints or blood vessels. We further characterized the FOI patterns and sorted the scans into groups based on the assumed diagnosis (Pso/PsA, RA, and healthy controls), which was compared with the physician's diagnosis. Furthermore, the associations between CV risk factors and imaging findings were investigated by regression analyses. Results: We included FOI scans of patients with Pso/PsA (n = 80), RA (n = 78), and healthy controls (n = 25). Subclinical skin enhancement on the back of their hands was more common in Pso/PsA (72.5%) than in RA patients (20.5%) and healthy individuals (28.0%) (p < 0.001). Based on the FOI pattern, the majority of patients with Pso/PsA (72.5%), RA (76.9%), and healthy controls (68.0%) were classified correctly using the physician-based diagnosis as reference (overall agreement of 74%, kappa = 0.57). No CV risk factors except body weight (kg) were associated with subclinical skin enhancement (OR 1.04, 95% CI 1.02-1.06; p < 0.001). Conclusion: Subclinical subdermal skin inflammation was common in Pso/PsA patients using FOI. Based on the FOI pattern, most patients with Pso/PsA and were classified with the correct diagnosis. We demonstrated an important influence of the body weight on our FOI results. FOI may be a helpful novel tool to study microcirculation in rheumatic diseases with skin involvement.

Epidemiology of Psoriasis and Comorbid Diseases: A Narrative Review

“…Active enthesitis and synovitis could be useful to identify subclinical PsA (178). Fluorescence optical imaging may be a helpful novel tool to analyze microcirculation in psoriasis/PsA patients (179).…”

Brodalumab Is Associated with High Rates of Complete Clearance and Quality of Life Improvement: A Subgroup Analysis of Patients with Psoriasis and Concomitant Psoriatic Arthritis

“…The early diagnosis and treatment of PsA are crucial to reduce the risk of joint damage, disability and comorbidities [ 7 , 8 , 9 ]. Since PsA usually occurs after the development of psoriasis [ 10 ], it is important that patients with psoriasis are routinely screened for signs of PsA.…”

New Perspectives on Diagnosing Psoriatic Arthritis by Imaging Techniques

“…After injection, a special camera detects the emissions of the fluorescent dye corresponding to the micro-vascularisation thus showing different patterns of inflammation. 32–35 Schmidt et al 33 applied this method to patients with psoriasis, PsA, RA and healthy controls and found that PsA and psoriasis patients have a specific FOI pattern that can be differentiated from healthy controls or even RA patients. Werner et al 32 performed a study where they demonstrated a correlation between the findings obtained by FOI, MRI, and US, while Wiemann et al 35 were able to differentiate between PsA and RA using this method.…”