Concept elicitation and development of a patient-centric conceptual disease model in chronic pruritus of unknown...

In some cases of chronic pruritus, no identifiable primary cause can be found, whether dermatologic, systemic, neurologic, or psychogenic. In such cases, the disease is referred to as CPUO. To date, little qualitative research has been conducted to understand patient perspectives and a patient-centered conceptual disease model (CDM) for CPUO is lacking. The aims of this study were: to explore the signs, symptoms, and impacts that patients associate with CPUO; and to use these qualitative findings to develop a conceptual disease model (CDM).

Telephone or web-based semi-structured qualitative interviews were conducted with American adults ≥ 18 years old with a clinician diagnosis of CPUO. Participants were identified at five US clinical sites and interviewed between November 2022 and September 2023. Their interview transcripts were coded using ATLAS.ti, and analyzed to determine the main signs, symptoms, and quality of life impacts of CPUO. Health status over the past month was self-rated.

The 20 participants were predominantly female (70%), and White (50%) or Asian (40%). Their mean (SD) age was 42.7 (22.4) years. Participants were generally single (65%), employed (65%), and in good (70%) to very good health (15%). All participants reported itch. Other common symptoms included raw skin (85%), stinging (70%), burning (70%), and dry or rough skin (70%). Participants declared itch (55%) to be the worst symptom. In terms of domains impacted, participants with CPUO frequently cited day-to-day activities (90%), sleep (80%), and work or school (70%). Participants reported the domain on which CPUO had the worst impact was sleep (59%). A patient-centric CDM was developed based on these findings.

This first non-interventional qualitative study of adults with CPUO has identified, described, and substantiated the symptoms and impacts of CPUO, which will help define key concepts for patients with CPUO. Itch was the disease-defining symptom of CPUO, and sleep disturbance was its main impact. These and other findings could help physicians make informed clinical decisions about CPUO, and help researchers design CPUO studies with appropriate endpoints.