Healthcare Resource Utilization and Economic Burden Across Clinical Phenotypes of Moderate-to-Severe Atopic Dermatitis in United States Dermatology Facilities

Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by intense itch and recurrent lesions that impose clinical and economic burden. The individual and combined contributions of itch intensity and lesion severity to healthcare resource utilization (HCRU) and costs are not well defined. This study characterized real-world clinical phenotypes of moderate-to-severe AD based on itch and lesion severity and quantified their associations with HCRU and healthcare charges. Methods: A retrospective cohort study was conducted using linked electronic health records and claims data from the OMNY Health Dermatology Platform (January 2022–June 2024). Patients aged ≥ 12 years with moderate-to-severe AD, defined by prescription treatment, were included. Patients were stratified into four clinical phenotypes based on their scores on the Itch Numerical Rating Scale (NRS) and Investigator Global Assessment (IGA): moderate itch and moderate lesions (MI-ML), severe itch and moderate lesions (SI-ML), moderate itch and severe lesions (MI-SL), and severe itch and severe lesions (SI-SL). Annualized all-cause HCRU and total healthcare charges were assessed using multinomial propensity score weighting. Logistic regression identified predictors of high total charges (≥ 90th percentile). Results: Among 4433 patients with moderate-to-severe AD, phenotype distribution was MI-ML (33%), SI-ML (43%), MI-SL (4%), and SI-SL (21%). While HCRU event rates (hospitalizations, emergency visits) were similar across phenotypes, mean annual total charges differed notably. Compared with MI-ML ($23,697), charges increased with severe itch (SI-ML: + $2197), severe lesions (MI-SL: + $3705), and both severe itch and lesions (SI-SL: + $10,448), driven mainly by pharmacy and outpatient costs. Mean annual charges were highest in SI-SL ($34,145), followed by MI-SL ($27,402), SI-ML ($25,894), and MI-ML ($23,697). Severe itch alone was associated with elevated pharmacy expenditures, whereas severe lesions primarily increased outpatient costs. In multivariable models, biologic use, systemic therapy, and comorbidities were predictors of high total charges. Conclusion: Both itch intensity and lesion severity independently and additively contributed to HCRU and economic burden of moderate-to-severe AD. Severe itch primarily increased pharmacy spending, while severe lesions drove outpatient costs. The combined phenotype of severe itch and lesions incurred the highest overall charges, underscoring the need for phenotype-informed, comprehensive AD management strategies.