BACKGROUND: Vitiligo is characterized by depigmented patches resulting from loss of melanocytes. Phototherapy has emerged as a prominent treatment option for vitiligo, utilizing various light modalities to induce disease stability and repigmentation.
OBJECTIVE: This narrative review aims to explore the clinical applications and molecular mechanisms of phototherapy in vitiligo.
CONCLUSIONS: The review evaluates existing literature on phototherapy for vitiligo, analyzing studies on hospital-based and home-based phototherapy, as well as outcomes related to stabilization and repigmentation. Narrowband ultra-violet B, that is, NBUVB remains the most commonly employed, studied and effective phototherapy modality for vitiligo. Special attention is given to assessing different types of lamps, dosimetry, published guidelines, and the utilization of targeted phototherapy modalities. Additionally, the integration of phototherapy with other treatment modalities, including its use as a depigmenting therapy in generalized/universal vitiligo, is discussed. Screening for anti-nuclear antibodies and tailoring approaches for non-photo-adapters are also examined.
CONCLUSIONS: In conclusion, this review provides a comprehensive overview of phototherapy for vitiligo treatment. It underscores the evolving landscape of phototherapy and offers insights into optimizing therapeutic outcomes and addressing the challenges ahead. By integrating clinical evidence with molecular understanding, phototherapy emerges as a valuable therapeutic option for managing vitiligo, with potential for further advancements in the field.

Phototherapy is an extremely effective and established therapeutic modality in a variety of dermatological disorders. However, there has been a constant concern with respect to its long-term usage as some of the studies have identified the risk of cutaneous malignancy associated with phototherapy. The carcinogenic potential of PUVA has been demonstrated in most US studies; however, the studies done on Asian and Arabian-African population have not corroborated similar findings, thus suggesting that the darker skin may confer protection against the development of cutaneous malignancy following phototherapy. The main aim of the present study was to assess the safety of phototherapy (bath PUVA and NBUVB) in Indian population (Fitzpatrick skin types IV and V) with respect to its carcinogenic potential and to determine the maximum cumulative dose that our patients could tolerate without developing any untoward complications such as cutaneous malignancy. All patients who received phototherapy between January 2006 and October 2016 were enrolled in the study. Details such as cumulative dose, number of phototherapy sessions received, indication for phototherapy, adverse effects such as pigmentary changes, new growths on the skin surface following the therapeutic sessions were entered in a predesigned proforma. This ambispective study had 1300 patients who had received phototherapy over a period of 10 years. A total of 929 patients had received PUVA, and the remaining 371 patients had received NBUVB for various dermatological indications. The average follow-up period for PUVA was 3 years and 6.5 years for NBUVB. The maximum cumulative dose of UVA and UVB that could be safely administered in our patients was 2085 J/cm2 and 1985 mJ/cm2, respectively. None of our patients developed any features of cutaneous malignancy during their follow-up. Both bath-PUVA and NBUVB are safe and efficacious in treating patients of darker skin types (IV and V). The risk of developing cutaneous malignancy is negligible in this subset of patients. However, more studies need to be done on the Asian population to substantiate the same.

Conventional, full-body phototherapy equipment is costly and therefore patients are usually treated in dermatology centres. Such office-based therapy is often not feasible for those patients who live far away from a phototherapy centre due to lost time and wages, inability to travel because of extensive skin disease, or prohibitive travel costs. Home phototherapy has emerged as a modality that meets the needs of those patients. Our aim was to review available studies on UV sources, treatment protocols, efficacy, and safety of home phototherapy. A literature review was conducted on PubMed using the terms \"home\" AND \"phototherapy\" AND (\"guide\" OR \"approach\" OR \"review\" OR \"protocol\"). From the data extracted, narrowband UVB (311 nm) offers the best balance between safety and efficacy and is recommended for home phototherapy by most authors. Treatment is safe and possible adverse effects are related to overexposure (erythema, blistering). The usual treatment protocol was administering treatments on alternating days, including weekends, with dosing based on the patient\'s Fitzpatrick skin type. We also provide information on the available home phototherapy systems in Canada and their reimbursement. Home phototherapy is underused in Canada. Narrowband UVB phototherapy sources equipped with a 3-dimensional panel provides a practical and safe option.