Two-Dimensional Planimetry for Alopecia Areata Severity Evaluation Compared With Severity of Alopecia Tool: A Pilot Study

This pilot study involved 93 patients with Alopecia Areata (AA) and aimed to validate the Severity of Alopecia Tool (SALT) score using planimetric surface area measurement of alopecic patches. The study found that the mean value and range of planimetric surface area varied across different severity categories (S1 to S4). The study also compared the SALT-Initial (SALT-I) and SALT-Photograph (SALT-P) methods, finding that SALT-P had a clearer correlation with less overlap between categories, suggesting it as a more reliable method. However, the study noted inconsistencies in differentiating between S1, S2, and S3 categories and potential subjectivity with SALT. The study concluded that planimetric surface area measurement could be a helpful supplementary indicator, especially for the S1, S2, and S3 categories. The study acknowledged limitations such as distortion when converting a three-dimensional structure to a two-dimensional image, especially for large alopecic patches, and suggested a larger-scale study for establishing reference ranges in various populations.