The purpose of this study is to determine if vitiligo patients develop tolerance to ultraviolet light therapy, a type of treatment available for vitiligo.

Patients with vitiligo received 6-9 ultraviolet B treatments, 2 to 3 times weekly. Minimal erythema dose (MED) testing was done at baseline and after all treatments; the percent change in MED was analysed as a measure of photoadaptation. The percent decrease in cyclobutane pyrimidine dimers (CPDs) over 24 hours after a single exposure of 1 MED was analysed on vitiliginous and normal skin.

• Procedure: 6 to 9 ultraviolet B treatments
• Procedure: Skin biopsies

Inclusion Criteria:

For inclusion, the subject must:

1. Be at least 18 years old
2. Be otherwise healthy
3. Have a diagnosis of vitiligo affecting > 5% body surface area (BSA)
4. Have two depigmented lesions on opposite sides of the body that can be biopsied at the end of TARGETED UVB PHOTOTHERAPY treatment
5. Agree to abide by the Investigator's guidelines regarding photosensitizing drugs
6. Have a negative pregnancy test at baseline if female of childbearing potential
7. Be able to understand the requirements of the study, the risks involved, and is able to sign the informed consent form
8. Agree to follow and undergo all study-related procedures

Exclusion Criteria:

Subjects will be excluded if any of the following apply:

1. Women who are lactating, pregnant, or planning to become pregnant
2. Patients with a recent history of serious systemic disease
3. Patients with a known history of photosensitivity
4. Concomitant use of systemic or topical treatments for vitiligo. Patients must discontinue PUVA or oral corticosteroid therapy for 4 weeks prior to the start of any treatment. If a patient is taking any vitamins or dietary supplements, the patient must discontinue them for the duration of the study. Topical therapy such as corticosteroids, topical immunomodulators (e.g., Protopic or Elidel), vitamin D derivatives (e.g., Dovonex), or UVB phototherapy must be discontinued for 2 weeks prior to the start of study treatment.
5. Patients diagnosed to be immunosuppressed for any reason (e.g., HIV infection, lupus, cancer, organ transplant, or chronic use of oral immunosuppressive agents).
6. Any reason the investigator feels the patient should not participate in the study