If the spots are on the hands and legs and have been there for more than 3 years, it can take a few months. Phototherapy sessions are done 2–3 times a week. Spots on a large area of the body may require full body treatment in a clinic or hospital. UVB broadband and narrowband lamps can be used, but narrowband ultraviolet peaked around 311 nm is the choice. It has been constitutively reported that a combination of UVB phototherapy with other topical treatments improves re-pigmentation. However, some people with vitiligo may not see any changes to skin or re-pigmentation occurring. A serious potential side effect involves the risk of developing skin cancer, the same risk as an overexposure to natural sunlight.Ultraviolet light (UVA) treatments are normally carried out in a hospital clinic. Psoralen and ultraviolet A light (PUVA) treatment involves taking a drug that increases the skins sensitivity to ultraviolet light, then exposing the skin to high doses of UVA light. Treatment is required twice a week for 6–12 months or longer. Because of the high doses of UVA and psoralen, PUVA may cause side effects such as sunburn-type reactions or skin freckling.Narrowband ultraviolet B (NBUVB) phototherapy lacks the side-effects caused by psoralens and is as effective as PUVA. As with PUVA, treatment is carried out twice weekly in a clinic or every day at home, and there is no need to use psoralen. Longer treatment is often recommended, and at least 6 months may be required for effects to phototherapy.
Triggers may include inflammatory skin conditions, burns, intralesional steroid injections and abrasions.Other conditions with similar symptoms include the following:

Albinism
Halo nevus
Idiopathic guttate hypomelanosis (white sunspots)
Piebaldism
Pityriasis alba
Postinflammatory hypopigmentation
Primary adrenal insufficiency
Progressive macular hypomelanosis
Tinea versicolor
Tuberculoid leprosy

Treatment
There is no cure for vitiligo but several treatment options are available. The best evidence is for applied steroids and the combination of ultraviolet light in combination with creams. Due to the higher risks of skin cancer, the United Kingdoms National Health Service suggests phototherapy be used only if primary treatments are ineffective. Lesions located on the hands, feet, and joints are the most difficult to repigment; those on the face are easiest to return to the natural skin color as the skin is thinner in nature. Immune mediators
Topical preparations of immune suppressing medications including glucocorticoids (such as 0.05% clobetasol or 0.10% betamethasone) and calcineurin inhibitors (such as tacrolimus or pimecrolimus) are considered to be first-line vitiligo  treatments.In July 2022, ruxolitinib cream (sold under the brand name Opzelura) was approved for medical use in the United States for the treatment of vitiligo. Phototherapy
Phototherapy is considered a second-line treatment for vitiligo. Exposing the skin to light from UVB lamps is the most common treatment for vitiligo. The treatments can be done at home with an UVB lamp or in a clinic. The exposure time is managed so that the skin does not suffer overexposure. Treatment can take a few weeks if the spots are on the neck and face and if they existed not more than 3 years.