428 Evaluating chronic pruritus prevalence, characteristics and effects on atopic dermatitis patients from a referral university hospital in São Paulo, Brazil: a cross-sectional study
Authors: Soares Georgia Biazus , Leão Orfali Raquel , Averbach Beatriz Lacerda , Yosipovitch Gil , Aoki Valeria 
Published: June 2023

Abstract
Chronic pruritus is one of the predominant symptoms of atopic dermatitis (AD), with one study showing that over 90% of patients with AD experience itch at least once a day. A multicenter, retrospective study in southern and southeastern Brazil found that at least 77% of patients had moderate to severe AD, and 55% experienced pruritus. However, this study did not specifically assess the characteristics of the itch associated with AD. Atopic dermatitis is also known to have a significant impact on quality of life, and has a detrimental effect on mental health, school and work performance, and social interactions. A study assessing patients with AD seen at the Dermatology Clinic at the University of Sao Paulo School of Medicine found that AD severely impacted patient scores on the Dermatology Life Quality Index (DLQI). Although the DLQI measures the impact of dermatologic diseases on Health-Related Quality of Life, it is not itch-specific. The itch-specific quality of life (ItchyQoL), a pruritus-specific instrument, was developed in order to better assess the impact of chronic pruritus on patients’ health-related quality of life. It has since been validated in over 22 European countries with a high degree of reliability and internal consistency across multiple languages. Since it is known that AD is phenotypically and molecularly different in ethnic populations, the diverse patient population found in São Paulo, Brazil represents an opportunity to further the understanding of AD in these individuals. Therefore, we conducted a large-scale, prospective study on the prevalence, severity and quality of life impacts of pruritus in patients with AD from a referral university hospital in São Paulo, Brazil to further strengthen the current understanding of this unique disease entity in this diverse patient population. Additionally, the association of itch intensity with the clinical severity of AD measured by objective, validated assessment tools will allow providers to better understand and manage chronic pruritus in this unique patient population. The primary objective of this cross-sectional study is to evaluate the prevalence and severity of itch in patients with Atopic Dermatitis (AD) in São Paulo, Brazil. The secondary objective of this study is to describe the characteristics of itch in this population and its effect on quality of life by using validated itch questionnaires and itch quality of life tools. The third objective of this study is to describe the clinical severity of AD in this patient population and its association to itch intensity. We conducted a cross-sectional study of patients aged 15–65 years old with atopic dermatitis who attended the Atopic Dermatitis Clinic at the Department of Dermatology, University of Sao Paulo Medical School over a 15-month period. Patients who experienced pruritus were asked to complete three validated questionnaires: The Itch Questionnaire, the ItchyQoL questionnaire and the Patient Oriented Eczema Measure. All itchy subjects were also asked to measure their perception of pruritus with a 10-cm NRS scale. The extent of disease was also assessed using the Eczema Area and Severity Index and the Validated Investigator Global Assessment scale for Atopic Dermatitis (vIGA). Results will be available to be presented at the conference. Finalized results of the study are pending.