Vitiligo is an acquired depigmentation disorder that is characterized by chronic and progressive loss of functioning skin and / or melanocytes of hair follicles. Melanocytes are found in the epidermis layer of the skin and produce melanin, the pigment that gives color to the skin and hair. The loss of epidermal melanocytes in vitiligo causes the loss of melanin pigment which leaves the affected area white.

Ultraviolet B Narrowband (NB-UVB) phototherapy has been used successfully for the treatment of inflammatory skin disorders and pigments including atopic dermatitis, psoriasis, mycosis fungoides, polymorphous light eruptions, and vitiligo.