The Impact of Pain and Itch on Functioning and Health-Related Quality of Life in Systemic Sclerosis: An Exploratory Study

CONTEXT: Pain and itch are common symptoms reported by patients with systemic sclerosis (SSc; scleroderma), which can markedly diminish function and health-related quality of life (HRQL). OBJECTIVES: The aim of this exploratory study was to examine the impact that pain, itch, and the interaction of both have on function (depressive symptoms, overall disability, fatigue, sleep disturbance) and HRQL in patients with SSc. METHODS: A total of 964 patients from the Canadian Scleroderma Reserch Group Registry completed questionnaires measuring itch and pain severity, function, and HRQL. Multiple regression analyses were performed to examine the impact that pain, itch, and pain × itch interaction have on each outcome variable while controlling for demographic measures. A P-value of ≤0.01 was required for a difference to be deemed statistically significant. RESULTS: Our results revealed that patients with SSc who reported higher pain and itch severity were also more likely to have greater depressive symptoms, overall disability, sleep and fatigue problems, even when demographic measures were controlled for (P-values ≤0.001). Similar results were obtained for HRQL, regardless of the domains (P-values ≤0.001). A significant association between pain × itch interaction and sleep (P = 0.002), physical functioning (P = 0.003), and general health (P ≤ 0.001) variables also was found. Further investigation of the nature of the pain × itch interaction showed that the effect of pain severity on outcome variables diminishes as itch severity increases. CONCLUSION: Both pain and itch appear to have a detrimental impact on functioning and HRQL in patients with SSc, suggesting that more targeted approaches to symptom management are warranted.