Although vitiligo is difficult to cure, recurrences are frequent after treatment, and many patients suffer from concerns about recurrence as well as disease. Psoriasis, another indication for ultraviolet radiation treatment, has been established that it can safely and effectively reduce the recurrence of psoriasis through monthly maintenance therapy.

The aim of this study was to evaluate the efficacy of Narrow-band UV-B therapy for the prevention of relapse in vitiligo.

For a total period of 12 months, perform Narrow-band UV-B treatment once a month. Check for signs of enlarged vitiligo lesions at 3-month intervals for a total period of 12 months.

An independent evaluator will obtain the score of vitiligo area (Vitiligo Extent Score) from comparing clinical photographs of before registration and after the clinical trial, and judge whether vitiligo is recurred. This study is a randomized controlled trial, and the investigators plan to compare the recurrence rates of the experimental and control groups using the Chi-squared test.

Inclusion Criteria:

1. Patients with age of 19 years or older
2. Patients of generalized vitiligo with lesions on the trunk
3. Patients who had treated with Narrow-band UV-B therapy previously and achieved more than 75% lesion improvement
4. Patients who voluntarily agreed to participate in the study

Exclusion Criteria:

1. Patients under the age of 19
2. Patients with localized vitiligo and segmental vitiligo
3. Patients who are in a state of physical or mental impairment to perform treatment or pregnant
4. Patients with spreading of vitiligo lesions
5. Patients who do not want to do thie study or who refuse to write a consent form
6. Any other person deemed unsuitable for the examination at the discretion of the examiner