The relative utilities of disease severity measures for atopic dermatitis (AD) were described in a commentary article published in the British Journal of Dermatology.
In routine clinical practice, the Investigator’s Global Assessment (IGA) and affected body surface area (BSA) are often used for simple, rapid assessment of eczema severity. In a clinical trial comparing multiple metrics, a composite measure of both IGA and BSA (IGAxBSA) emerged as reliable and accurate, although insufficient for capturing subjective outcomes, it was noted.
Clinical trials of AD often utilize the Eczema Area and Severity Index (EASI) and SCORing Atopic Dermatitis (SCORAD) scores as primary outcome measures. However, given their complexity and length, these scales are unwieldy for use in routine clinical practice. By comparison, the 5-point IGA static scale can be used to obtain an easy summary of disease severity. Similarly, BSA relies on the percentage of affected skin to estimate the effects of AD on patients. The author cited a systematic review of published clinical trials on eczema, in which a composite score calculated by multiplying IGA by the BSA was found to have a significant positive correlation with EASI and SCORAD (both P <.001). This correlation with EASI was maintained across multiple treatment timepoints and in multiple strata of disease severity. IGAxBSA was also found to be relevant across demographic categories and skin types. However, the correlations with the Peak Pruritis Numerical Rating Scale and patient-rated quality of life were weaker, suggesting that IGAxBSA may be insufficient for measuring subjective outcomes.
Given these data, the commentary article advocated for the use of IGAxBSA in routine clinical practice to obtain a snapshot of disease severity. However, in assessing patients’ quality of life, more intensive measures may be necessary.
Futamura M. Easy assessment tool for disease severity of atopic dermatitis in clinical practice. Br J Dermatol. Published online February 6, 2022. doi:10.1111/bjd.20951