Phototherapy is used to treat vitiligo using both its immunosuppressive effects and its ability to stimulate melanocyte activity.¹ It’s effective for active disease by promoting T-cell apoptosis, suppressing inflammatory cytokines, stimulating interleukin-10, and decreasing the number of epidermal Langerhans cells serving as antigen-presenting cells. It is also effective for patients with stable disease as it supports melanocyte proliferation and migration from the hair follicles to the epidermis.¹ 

The different types of phototherapy include psoralen ultraviolet-A (PUVA) radiation, ultraviolet-B (narrow-band [NB-UVB][310-315 nm wavelength], and excimer laser [EL][308 nm wavelength], lamp) radiation. PUVA and NB-UVB serve as the main forms of treatment for generalized vitiligo, while EL is commonly used to treat localized vitiligo and is popular among pediatric patients.² 

NB-UVB and PUVA 

NB-UVB is currently considered the standard of care and preferred over PUVA because it lessens oxidative stress-induced damage and has fewer limitations and side effects. While PUVA carries the risk of phototoxic effects, nausea, skin cancer, and cannot be used on children and pregnant women, NB-UVB does not require a photosensitizer, can be administered with a lower cumulative dose, has demonstrated superior overall treatment response, and has adverse effects that are well tolerated and disappear hours after treatment (erythema, itching, mild burning or pain).^{2, 3} Under special conditions–such as patients with refractory vitiligo or higher Fitzpatrick skin phototypes–PUVA phototherapy still remains an option.⁴ 

NB-UVA efficacy 

The efficacy of NB-UVB for vitiligo, especially nonsegmental vitiligo, is highly supported; for instance, a retrospective review found that repigmentation persisted in 80% of patients one year after discontinuation of NB-UVB.⁵ A longer treatment duration has been found to improve treatment outcomes, with at least 6 months required to determine any responsiveness to NB-UVB phototherapy and at least one year required to obtain maximal results.² The face and neck were the most responsive to NB-UVB, followed by the trunk, extremities, and hands and feet. Barriers to repigmentation include disease activity, autoimmune state, large targeted body surface area, and concurrence of poliosis.² 

Excimer laser 

EL is just as⁶ or more effective⁷ in treating vitiligo, does not expose normal skin to radiation, and can target areas such as the ears and genitals. A 2022 study found that during a follow-up of 3.38 years after EL treatment, repigmentation persisted in 80% of facial, 40% of body, and 20% of extremity lesions.⁸ EL is most effective when used early in the clinical process for segmental vitiligo.⁹ Recent studies have also shown that EL treatment should be combined with topical interventions such as tacrolimus, pimecrolimus, or halometasone.¹⁰ Repigmentation is fastest with 3 sessions per week with a minimum of 20 treatments recommended.^{11, 12} Common adverse effects of EL include erythema, pruritus, blistering, and perilesional hyperpigmentation.¹³ 

Current evidence suggests that while no vitamin D analogs were found to enhance the efficacy of PUVA or EL for vitiligo, the combination of topical calcipotriol or tacalcitol with NB-UVB increases the rate of response to treatment; the effect of tacalcitol was found to be greater than that of calcipotriol.¹⁴ 

As the therapeutic options for vitiligo expand, phototherapy remains a versatile and effective treatment, leveraging both immunosuppressive effects and the stimulation of melanocyte activity. With various modalities available, dermatologists can tailor their approach based on the patient's condition and specific requirements. 

1. Zubair R, Hamzavi IH. Phototherapy for Vitiligo. Dermatol Clin. 2020;38(1):55-62. doi:10.1016/j.det.2019.08.005 
2. Bae JM, Jung HM, Hong BY, et al. Phototherapy for Vitiligo: A Systematic Review and Meta-analysis. JAMA Dermatol. 2017;153(7):666-674. doi:10.1001/jamadermatol.2017.0002 
3. Pacifico A, Leone G. Photo(chemo)therapy for vitiligo. Photodermatol Photoimmunol Photomed. 2011;27(5):261-277. doi:10.1111/j.1600-0781.2011.00606.x 
4. Rodrigues M, Ezzedine K, Hamzavi I, Pandya AG, Harris JE; Vitiligo Working Group. Current and emerging treatments for vitiligo. J Am Acad Dermatol. 2017;77(1):17-29. doi:10.1016/j.jaad.2016.11.010 
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8. Sethi S, Silverberg N. Short and Long-Term Outcomes of 308-nm Laser for Pediatric Vitiligo. J Drugs Dermatol. 2022;21(7):773-775. doi:10.36849/JDD.6895 
9. Majid I, Imran S. Excimer light therapy in childhood segmental vitiligo: Early treatment gives better results. Dermatol Ther. 2020;33(3):e13408. doi:10.1111/dth.13408 
10. Li L, Liang Y, Hong J, Lan L, Xiao H, Xie Z. The effectiveness of topical therapy combined with 308-nm excimer laser on vitiligo compared to excimer laser monotherapy in pediatric patients. Pediatr Dermatol. 2019;36(1):e53-e55. doi:10.1111/pde.13726 
11. Hofer A, Hassan AS, Legat FJ, Kerl H, Wolf P. Optimal weekly frequency of 308-nm excimer laser treatment in vitiligo patients. Br J Dermatol. 2005;152(5):981-985. doi:10.1111/j.1365-2133.2004.06321.x 
12. Hui-Lan Y, Xiao-Yan H, Jian-Yong F, Zong-Rong L. Combination of 308-nm excimer laser with topical pimecrolimus for the treatment of childhood vitiligo. Pediatr Dermatol. 2009;26(3):354-356. doi:10.1111/j.1525-1470.2009.00914.x 
13. Speeckaert R, van Geel N. Vitiligo: An Update on Pathophysiology and Treatment Options. Am J Clin Dermatol. 2017;18(6):733-744. doi:10.1007/s40257-017-0298-5 
14. Liu X, Yao Z, Wang Y, Chai L, Zhou X. Vitamin D analogs combined with different types of phototherapy in the treatment of vitiligo: A systematic review of randomized trials and within-patient studies. Int Immunopharmacol. 2022;109:108789. doi:10.1016/j.intimp.2022.108789