An open-label, intergroup study to evaluate the efficacy and safety of N-acetyl-cysteine in patients with vitiligo

INTERVENTION: randomized controlled trial CONDITION: vitiligo ; vitiligo PRIMARY OUTCOME: 1) Comparison of NAC‐administered group and non‐NAC‐administered group based on 3‐grade evaluation of vitiligo image in comparison period (improvement: +1, unchanged: 0, worsening: ‐1) SECONDARY OUTCOME: 1) Changes in three‐step evaluation of vitiligo images (improved: +1, unchanged: 0, worsened: ‐1) by continuous administration of NAC during the continuous observation period; 2)Quantitative evaluation of vitiligo based on images of vitiligo sites to be evaluated in the comparison period and continuous observation; 3)Changes in blood glutathione concentration during the comparison period and the continuous observation period; 4)Changes in QOL scores during the comparison period and the continuous observation period INCLUSION CRITERIA: 1)Patients diagnosed with vitiligo 2)Written informed consent by his or her own will 3)20 years old over (Both of male and female) 4)Patients judged by physicians to be poorly effective with standard drugs and phototherapy