Evaluation of the effect of disease duration in generalized vitiligo on its clinical response to narrowband ultraviolet B phototherapy

Background/Purpose Narrowband ultraviolet B (NB-UVB) has been accepted as an effective therapy for generalized vitiligo. On the other hand, different factors seem to contribute to a good response. The purpose of this study is to evaluate the influence of disease duration on its clinical response to NB-UVB phototherapy. Methods In this open and uncontrolled study, vitiligo was considered recent when the duration of disease was less than or equal to 4 years and long standing when it was greater than 4 years. The patients received NB-UVB thrice weekly with an initial dose of 200?mJ/cm2 and 10% increments at each subsequent treatment. After categorizing the clinical response to four groups (mild, moderate, good, and excellent), duration of disease and clinical response to NB-UVB were correlated statistically using the t-test. Results There were 63 patients: 34 women and 29 men, aged 660 years. The mean of disease duration was 10.13 +/- 9.1 years. Vitiligo was recent in 26 and long standing in 37 patients. The mean of overall response was 51.94 +/- 18.48%. Higher grades of response were more prevalent in patients with recent vitiligo than those with long-standing disease, and there was also statistically significant difference in overall response between these two groups of disease duration (P?=?0.023). Conclusion The early treatment of generalized vitiligo may enhance the chance of successful repigmentation.