Development and validation of facial vitiligo area scoring index (F-VASI) using the fingertip unit
Bae JM, Zubair R, Ju HJ, Kohli I, Lee HN, Eun SH, Lyons AB, Vellaichamy G, Han TY, Lim HW, and Hamzavi IH. Development and validation of facial vitiligo area scoring index (F-VASI) using the fingertip unit. Pigment Cell Melanoma Res 2021; 34(2):436.
Pigment Cell Melanoma Res
Background: Facial involvement has often been evaluated separately in clinical trials, because facial involvement is not only the most critical factor in the patient's life, but also the area with the greatest response to treatment. However, no reliable measurement tools for facial vitiligo are available thus far.
Objective: To develop and validate a practical instrument for assessing facial vitiligo.
Methods: Facial Vitiligo Area Scoring Index (F-VASI) was measured as the sum of all fingertip units (FTUs) of each vitiligo lesion on the face. In the validation study, a total of 41 dermatologists evaluated photographs of 17 patients with facial vitiligo as F-VASI using the FTU twice at an interval of 2 weeks.
Results: F-VASI showed remarkably high accuracy (concordance correlation coefficient: 0.937, smallest detectable change: 2.0 FTU) as well as high intra-rater reliability (intraclass correlation coefficient: 0.926) and inter-rater reliability (0.909).
Conclusion: F-VASI is an accurate, reliable, and practical instrument for assessing the extent of facial involvement in vitiligo patients. It can be used alone to sensitively assess small scattered lesions on the face, as well as to complement the hand unit when performing VASI for generalized vitiligo.