Digital image analysis vs. clinical assessment to evaluate repigmentation after punch grafting in vitiligo

Background Repigmentation as a treatment outcome in vitiligo is not assessed in a standard way, making results of clinical trials hard to compare. Different types of repigmentation assessments after punch grafting have not been compared so far. Objective To compare assessments of repigmentation by a digital image analysis system (DIAS) with those of clinical observers and patients after punch grafting for vitiligo. Methods One vitiligo patch was selected in each patient (n = 21). This patch was treated with the punch grafting technique. The grade of repigmentation (%) after 3 months was assessed by: (i) DIAS; (ii) 3 clinical observers; and (iii) the patient, scoring the grade of repigmentation on photographs. Physicians and patients also evaluated the global result on a 7-point scale. Results There was an almost perfect agreement between the three clinical observers and the DIAS (ICC 0.83). As expected, variation was found between the clinical observers. Patients' scores showed a moderate agreement with the DIAS (ICC 0.49) and a poor agreement with the physicians (ICC 0.28). Overall, the patients were more satisfied with the results than the physicians. Conclusions Whereas the results of the digital and clinical assessments were comparable, patients' ratings diverged. The DIAS can overcome the inevitable differences between observers, which are intrinsic to a visual grading method, and is advisable for clinical trials on vitiligo to objectively assess repigmentation in limited lesions. Received: 9 December 2011; Accepted: 18 April 2012