A Practical Guide for Assessment of Skin Burden in Patients With Psoriatic Arthritis

Objective Rheumatologists play a pivotal role in the management of patients with psoriatic arthritis (PsA). Due to time constraints during clinic visits, the skin may not receive the attention needed for optimal patient outcome. Therefore, the aim of this study was to select a set of core questions that can help rheumatologists in daily rheumatology clinical practice to identify patients with PsA with a high skin burden. Methods Baseline data from patients included in the Dutch South West Psoriatic Arthritis (DEPAR) cohort were used. Questions were derived from the Skindex-17 and Dermatology Life Quality Index (DLQI) questionnaires. Underlying clusters of questions were identified with an exploratory principal component analysis (PCA) with varimax rotation, after which a 2-parameter logistic model was fitted per cluster. Questions were selected based on their discrimination and difficulty. Subsequently, 2 flowcharts were made with categories of skin burden severity. Clinical considerations were specified per category. Results In total, 413 patients were included. The PCA showed 2 underlying clusters: a psychosocial domain and a domain assessing physical symptoms. We selected these 2 domains. The psychosocial domain contains 3 questions and specifies 4 categories of skin burden severity. The physical symptoms domain contains 2 questions and categorizes patients in 1 out of 3 categories. Conclusion We have selected a set with a maximum of 5 questions that rheumatologists can easily implement in their consultation to assess skin burden in patients with PsA. This practical guide makes the assessment of skin burden more accessible to rheumatologists and can aid in clinical decision making.