Product of Investigator Global Assessment and Body Surface Area (IGAxBSA): A practice-friendly alternative to the Eczema Area and Severity Index to assess atopic dermatitis severity in children

Background: Accurately documenting pediatric atopic dermatitis (AD) severity is important, but research tools, such as Eczema Area and Severity Index (EASI), are too time consuming for clinical settings. Product of the Physician Global Assessment and affected percentage of body surface area (PGA×BSA) is a new, rapid measure of psoriasis severity. Objective: To evaluate an Investigator Global Assessment and body surface area product (IGA×BSA) as an easy-to-use severity measure for pediatric AD. Methods: Patient-reported and objective disease severity measures were collected from 195 caretaker/child dyads (child age range, 5-17 years) with almost clear (Validated Investigator Global Assessment for AD [vIGA] of 1) to severe (vIGA of 4) AD. Data were assessed with Spearman coefficients and plots. Severity strata were proposed by using an anchoring approach based on the EASI. Results: IGA×BSA correlates better with the EASI than IGA alone (r = 0.924 vs r = 0.757, P < .001). Bland-Altman plot indicates high and consistent agreement between IGA×BSA and the EASI. Suggested severity strata for IGA×BSA are 0-30, mild; 30.1-130, moderate; and 130.1-400, severe (κ = 0.760). Limitations: The patient cohort was predominantly from the midwestern United States. Conclusions: IGA×BSA (using the vIGA) is a simple measure that correlates well with the EASI in patients with mild to severe pediatric AD. Future work is needed to affirm reliability across IGA scales and responsiveness to change.