A team of researchers has developed a set of core questions that may be helpful in guiding clinicians in clinical practice in their assessment of skin burden in patients with psoriatic arthritis (PsA). The guidance was published online in The Journal of Rheumatology.
In an effort to develop guidance on the clinical assessment of skin burden in patients with PsA, the group of European researchers evaluated baseline data of patients with PsA from the Dutch South West PsA (DEPAR) cohort who received usual care for their disorder. For question development, the researchers relied on the 17-item Skindex-17 and the 10-item Dermatology Life Quality Index (DLQI) questionnaires.
An exploratory principal component analysis (PCA) with varimax rotation was performed on the combined questionnaires to identify underlying clusters of questions. The investigators fitted a 2-parameter logistic (2PL) model per cluster. Afterwards, the investigators selected questions based on their difficulty and discrimination.
A total of 2 flowcharts were generated with the selected questions, which were arranged in chronological order, and categories of skin burden severity were elucidated. Several clinical considerations were formulated per category of skin burden severity.
Complete data for the Skindex-17 and DLQI questionnaires were available for 413 patients (mean age, 50.3 years; 50% male). At baseline, the median Psoriasis Area and Severity Index score for the population was 2.0. In the cohort, patients had a median of 2.0 swollen joints and 3.0 tender joints. Using the 36-item Short Form Health Survey, the general health-related quality of life score was 39.2 on the physical component summary scale and a median of 49.4 on the mental component summary scale.
The median scores on a symptoms subscale and psychosocial subscale of the Skindex-17 were 4.0 and 1.0, respectively. In addition, the median DLQI score in the overall cohort was 1.0.
The PCA provided the best fit with 2 underlying clusters of questions, including those related to the psychosocial impact of the disease and those related to physical symptoms. A total of 3 questions were selected to assess the psychosocial impact and 2 questions regarding physical symptoms.
Investigators specified 4 categories of skin burden severity in the psychosocial cluster and 3 categories in the physical symptoms cluster. According to the researchers, the answers should be based on patient experiences 1 week before their clinical visit, reflected by a 1-week recall period beforehand. Below is a brief description of each cluster, the questions within each cluster, and the possible answers.
Cluster 1: Psychosocial
Researchers explained that this cluster divides skin burden of patients with PsA into 4 categories based on the severity of the psychosocial burden associated with the skin. In the first question, patients are asked if they are embarrassed by their skin disease. An answer of “never” places the patient into category 1, but if they answer “rarely/sometimes” or “often/always,” the clinician should continue to the next question.
In the next question, the patient is asked if they often stayed home because of their skin disorder. An answer of “never” places the patient into category 2, but the clinician is instructed to continue to the next question if the patient answers with “rarely/sometimes” or “often/ always.” The next question pertains to whether the patient’s skin disorder has prevented them from studying or working; the patient falls into category 3 if not and category 4 if so.
Cluster 2: Physical Complaints
In the physical symptoms cluster, patients’ skin burden is divided into 3 categories based on the burden severity stemming from physical symptoms. Clinicians firstly ask the patient how itchy, painful, sore, or stinging their skin has been. An answer of “not at all” places the patient into category 1, but an answer of “a little/a lot/very much” prompts the physician to continue to the next question.
The second question pertains to whether the patient’s skin is irritated; an answer of “never/rarely/sometimes” places the patient into category 2, while an answer of “often/always” places the patient into category 3 (the highest burden in this domain).
According to the researchers, approximately 93% of all patients at baseline could be categorized into 1 of the 4 categories with the 2PL model of the psychosocial cluster. Approximately 96% of patients could be categorized by 12 months. All patients could be categorized in the physical symptoms cluster at both baseline and 1 year. A majority of patients fell into category 1 within the psychosocial cluster (57%) and category 3 within the physical symptoms cluster (64%) at baseline.
Researchers noted that the practical guide may represent “a good starting point for rheumatologists” to create an open dialogue with patients to discuss skin burden associated with PsA. “The practical guide will function as a tool for the rheumatologist to start the dialogue with their patients on skin burden, and the clinical considerations will subsequently aid in clinical decision making,” the researchers added.
Kasiem FR, Pasma A, Luime JJ, et al. A practical guide for assessment of skin burden in patients with psoriatic arthritis. J Rheumatol. Published online June 1, 2022. doi:10.3899/jrheum.210550