Phototherapy means treatment with light. For vitiligo, there are two main categories of phototherapy: narrow-band ultraviolet B (NB-UVB) and psoralen ultraviolet A (PUVA) light treatments. PUVA involves taking psoralen tablets or applying creams or baths to the skin before phototherapy. Although both NB-UVB and PUVA are effective, NB-UVB is the treatment of choice because it has been found to result in higher repigmentation rates and better colour match, and it is less likely to cause side compared to PUVA (Gawkrodger et al., 2008). Patients with darker skin tones may experience a better response to phototherapy
(Taieb et al., 2013). Phototherapy can be thought of as a tanning bed but with very specific light wave lengths.

Vitiligo is a disorder which increases inflammation in the body causing its own immune system to destroy colour-producing cells (melanocytes). Phototherapy is thought to suppress DNA synthesis which results in reduced inflammation, and to stimulate the production of melanocytes (Purokayastha et al., 2023, Taieb et al., 2013).

After being prescribed phototherapy, you will go to hospital-based appointments 2-3 times a week, depending on your response and the treatment availability. Phototherapy should last for a minimum of 6 months as that’s the time it may take to for some repigmentation to occur. The treatment will be continued as long as there is repigmentation with the maximum length of 2 years. This time limit minimizes the risk of developing skin cancer. The sessions will be discontinued if you experience severe side effects. Your dermatologist should monitor your response to the treatment with serial photographs every 2-3 months (Gawkrodger et al., 2008).

Phototherapy takes place in a specially designed light cabinet which is a little like a tanning bed. Depending on the extent of your vitiligo you might receive full-body treatment for which you will be given eye protection, or a more localized treatment in which fluorescent light tubes are positioned to target the areas affected with vitiligo directly. At first, the sessions may be very brief (less than 5 minutes) and then, depending on whether you experience any side effects, may be extended up to 30 minutes. You are required to inform the phototherapy team of any medical conditions you might have and any medication you take as those might make you more prone to burning during the sessions. You should follow the phototherapist’ advice on the use of ointments and sunscreen as those can affect UV light absorption and should not be applied prior to treatment but rather afterwards. You will be asked about your response to phototherapy and whether you experienced any burning (Purokayastha et al., 2023).

If you are prescribed PUVA treatment, you will be required to take a psoralen tablet 1-3 hours before the session or dissolve psoralen cream into bathwater and then soak in the water 30 minutes prior to the treatment. If you have more localised vitiligo, you may be required to apply a thin coat of psoralen cream onto the white patches 30 minutes prior to phototherapy rather than the tablets or a bath.

The treatment is considered very safe, with minimal side effects. The most common adverse effect is skin redness and burning which usually occurs within a day following the sessions and disappearing withing a few days. Slight redness in the vitiligo patches is perfectly normal and it indicates the treatment is working. Some patients might also experience itching, but it is generally not too bothersome. You might notice some sings of skin ageing (Taieb et al., 2013).

Psoralen is a chemical that makes you skin more sensitive to light. Since PUVA involves taking psoralen tablets, you are required to wear sunglasses for at least 8 hours after taking the tablet and take extra caution to apply sunscreen following the phototherapy session. Some patients report nausea caused by the tablets (Whitton et al., 2015).

Phototherapy is considered a second-line treatment (Beqvist & Ezzedine, 2020), meaning is it recommended for patients who did not have a good response to treatment with creams or ointments for vitiligo such as steroid creams or Protopic. It is recommended for patients whose vitiligo covers more than 10% of their body. You will not be given phototherapy if you ever had skin cancer or if you are pregnant (Purokayastha et al., 2023).

Phototherapy is a good option if you did not see any improvement in your vitiligo following other treatments or if your vitiligo is very widespread. Patients with darker skin tend to find the treatment more effective. Light therapy requires a great deal of commitment as you will have to attend all of your appointments for a minimum of 6 months. While most patients do see some repigmentation, it is important to keep in mind that the treatment is not effective for everyone and that some parts of the body, such as the hands and feet often do not respond well to phototherapy (Gawkrodger et al., 2008). Although not by much, phototherapy does increase the risk of skin cancer so if that is a disorder common in your family, this treatment may not be the best choice for you.

References

Bergqvist, C., & Ezzedine, K. (2020). Vitiligo: A Review. Dermatology, 236(6), 571–592. https://doi.org/10.1159/000506103
Gawkrodger, D. J., Ormerod, A., Shaw, L. B., Mauri-Sole, I., Whitton, M. E., Watts, M. R., Anstey, A. V., Ingham, J. D., & Young, K. (2008). Guideline for the diagnosis and management of vitiligo. British Journal of Dermatology, 159(5), 1051–1076.
https://doi.org/10.1111/j.1365-2133.2008.08881.x
Purokayastha, M. D., Moss, J., Davies, E., & Coulson, I. (2023). UVB phototherapy. DermNet. Retrieved May 28, 2023, from https://dermnetnz.org/topics/uvb-phototherapy
Taieb, A., Alomar, A., Böhm, M., Dell’Anna, M., De Pase, A., Eleftheriadou, V., Ezzedine, K., Gauthier, Y., Gawkrodger, D., Jouary, T., Leone, G., Moretti, S., Nieuweboer-Krobotova, L., Olsson, M., Parsad, D., Passeron, T., Tanew, A., Van Der Veen, W., Van Geel, N., . . . Picardo, M. (2013). Guidelines for the management of vitiligo: the European Dermatology Forum consensus. British Journal of Dermatology, 168(1), 5–19. https://doi.org/10.1111/j.1365-2133.2012.11197.x
Whitton, M. E., Pinart, M., Batchelor, J. M., Leonardi-Bee, J., González, U., Jiyad, Z., Eleftheriadou, V., & Ezzedine, K. (2015). Interventions for vitiligo. The Cochrane Library. https://doi.org/10.1002/14651858.cd003263.pub5