The goal of this clinical trial is to learn if adding topical tacrolimus or topical tyrosine to narrowband UVB phototherapy works to treat vitiligo in adults. It will also learn about the safety of both combinations.

The main questions it aims to answer are:

Which combination (UVB + tacrolimus or UVB + tyrosine) leads to greater skin repigmentation (color return) after 3 months of treatment? What side effects do participants experience with each combination? Researchers will compare three groups: UVB + tacrolimus, UVB + tyrosine, and UVB only to see which is more effective and safer.

Participants will:

Receive narrowband UVB phototherapy sessions two times per week at minimal erythema dose Apply either topical tacrolimus or topical tyrosine to their vitiligo patches twice daily Visit the clinic every one month for skin examination and photography Report any side effects or skin reactions

Study Design and Setting:

This is a randomized, intra-individual (within-patient) controlled, open-label clinical trial conducted at the outpatient dermatology clinic of a university hospital in Egypt. The study duration is from August 2025 to February 2026. A total of 69 patients with vitiligo were enrolled, with 67 completing the study.

For each enrolled patient, three comparable vitiligo patches were identified on the patient's body. Each patch was randomly assigned to one of three treatment regimens, allowing each patient to serve as their own control.

Phototherapy Procedure:

Narrowband UVB (NB-UVB) phototherapy was administered to all patches simultaneously using a full-body cabinet. Treatment was given twice weekly for 3 months, starting at the minimal erythema dose (MED) with incremental increases of 10-20% per session based on erythema response. The same phototherapy protocol was applied uniformly to all three patches on each patient.

Topical Treatments:

For patches assigned to combination therapy, the topical agent (either tyrosine 2% cream or tacrolimus 0.1% ointment) was applied by the patient at home twice daily (morning and evening) every day. Patches were clearly marked to the patients, and patients received standardized written instructions. Compliance was monitored by asking about remaining quantity of topical preparation at each follow-up visit.

Blinding and Assessment:

Although the trial was open-label for patients and treating physicians, outcome assessors were two independent dermatologists blinded to treatment allocation. Standardized digital photographs were taken under consistent lighting conditions at baseline and at 3 months. For each photograph and repigmentation percentage was determined via VESTA score.

Safety Monitoring:

At each phototherapy session (twice weekly), patients were assessed for acute adverse effects including erythema, pain, and pruritus (yes or no). Any adverse event requiring treatment interruption or discontinuation was recorded.

Data Management:

All data were collected on paper case report forms and then entered into an electronic database (Microsoft Excel) by independent data entry operator. The final dataset was exported to SPSS for analysis.

Inclusion Criteria:

• Patients aged 18-65 years with vitiligo who are candidates for narrowband UVB (NB-UVB) phototherapy.

Exclusion Criteria:

• Pregnant or lactating women.
• Patients who have received any systemic or topical treatment for vitiligo within the preceding three months.

IPD will not be shared because participants did not provide informed consent for data sharing beyond the primary study purpose, and the study is a single-center trial with a small sample size conducted in a routine clinical setting.