The clinical assessment of vitiligo engages an estimation of the affected body surface area. The Vitiligo Extent Score (VES) is the most widely used clinical rating scale for the overall vitiligo involvement of the body (extent), regardless of medication, treatment, or age. Over the years, the scale has emerged as a responsive instrument/tool to assess global and regional treatment response in patients with vitiligo. Reason? The measurement instrument allows monitoring the affected body surface area accurately and easily, in a standardized way.
There had been a lack of the standardization of outcome measures in vitiligo, which makes it difficult to compare the outcomes of different studies and therefore hampers vitiligo treatment recommendations. For clinical trials, the VES has been widely used to follow the extent of the chronic skin disorder and determine the treatment-related benefits. A good and validated scoring instrument like Vitiligo Extent Score permits valid measurement of the skin disorder’s extent, a necessary feature that allows the results of clinical trials to be accurately interpreted and compared.
Other frequently used rating scales for vitiligo include the Vitiligo Impact Patient Scale (to measure the quality of life in vitiligo), and the Vitiligo Noticeability Scale (for patient-reported outcome evaluation). These scales along with the VES can help in the improvement of vitiligo management, estimation of prognosis, understanding of the skin disorder’s progression, and the development of therapeutic options.
Design of the VES model
The original idea of the VES was based on clinical pictures of 10 different body locations, reflecting the degrees of vitiligo’s involvement. These Pictures were designed to mimic the natural evolution of nonsegmental vitiligo. The intent was to create a template that would allow easy comparison between the “real life” patients and the scoring sheet. ImageJ analysis was used to calculate percentage of depigmentation in each picture (e.g., 1%, 5%, 10%, 25%, 50%, and 75%).
However, over the years, several changes have been made in the VES to allow a more precise scoring, such as the possibility of selecting 1/2 and 1/4 of the involved area.
Vitiligo Extent Score – Components
The VES is made up of evaluation of body surface area. The pictures that reflect an individual’s extent of the vitiligo lesions can be selected by this instrument/tool. Based on the pictures, the calculator provides a score that can be expressed in percentage of an individual’s body surface area.
A score of 100% on the scale represents the ultimate loss of melanocytes (Universal Vitiligo), while a score of zero on the VES template represents no vitiligo.
The possible translation of the Vitiligo Extent Score into clinically relevant categories of extent would be a significant advantage compared with the currently available tool.