Clinical phenotyping of atopic dermatitis using combined itch and lesional severity: A prospective observational study.

Background Atopic dermatitis (AD) patients have heterogeneous clinical phenotypes, including different combinations of itch and lesional severity. Little is known about the characteristics and course of these subtypes. Objective To determine the characteristics, associations, burden, and course of AD patients using combined itch and lesional severity. Methods A prospective practice-based study was performed using questionnaires and physical examination (n=592). AD subsets were defined using verbal rating scale for average-itch combined with either EASI, objective- SCORAD or vIGA-AD as follows: mild-moderate itch and lesions (MI/ML), mild-moderate itch and severe lesions (MI/SL), severe itch and mild-moderate lesions (SI/ML), severe itch and lesions (SI/SL). Results At baseline, there were only weak-moderate correlations of numerical rating scales for worst-itch or average-itch, or SCORAD-itch with EASI, objective-SCORAD, body surface area, and vIGA-AD (Spearman's rho=0.32-0.62). Most patients had MI/ML (59.4-62.3%), followed by SI/ML (21.3%-29.1%), SI/SL (6.0%-12.9%), and MI/SL (3.8%-6.4%). Patients with SI/SL, followed by SI/ML and MI/SL, described their AD as being more severe overall and had worse impairment in sleep, mental health, and quality of life. However, those with MI/SL or SI/SL were far more likely to be classified as severe by a physician (multivariable logistic and linear regression, P Conclusion Combined itch and lesional severity appear to describe unique AD phenotypes. Further studies are needed to confirm these findings and understand the optimal treatments for these groups.