الفهرس 
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Abstract
Vitiligo is an acquired depigmentary disease. The disorder affects 1-3% of world population without any age, sex or racial predilection (Shah et al., 1991 and Njoo et al., 1998). Vitiligo has a profound negative psychological impact, especially in colored races (Millington and Levell, 2007). Although exact mechanism is not known but due to genetic predisposition, immune-mediated mechanism or other unidentified toxins, the melanocytes stop their function or they physically disappear in the affected epidermis while those in the hair follicle are usually spared (Flabella et al., 1995).
Vitiligo can begin at any age, but in 50% of cases it develops before the age of 20. The condition is slowly progressive. Hypomelanotic macules are usually first noted on the sun exposed areas of the skin, on the face or backs of the hands. The melanotic macules in vitiligo are found particularly in areas that are normally hyperpigmented e.g. the face, axillae, groins, areolae and genitalia (Lerner, 1971).
The treatment of vitiligo is based on the principles of stimulating the existing melanocytes in the affected area or repopulating it with functioning melanocytes (Gottschalk and Kidson, 2007). In sunny climates prescription of sunscreens is often necessary. Medical topical treatment includes pimecrolimus and tacrolimus ointment 0.1% (Leite, 2007). Treatment by systemic psoralens, 4, 5, 8-trimethylpsoralen (TMP) and 8-methoxypsoralen (8-MOP), combined with exposure to sunlight or light sources is effective. The use of topical applications of psoralens is hazardous and may result in blistering of the skin (Bleehen, 1972). Steroids, both systemic and topical preparations as 0.1% betamethasone valerate and 0.05% clobetasol propionate with or without ultraviolet light exposure through sun or artificial sources emitting ultraviolet A or narrow band ultraviolet B (NB-UVB) light are effective in producing repigmentation of areas of vitiligo (Leite, 2007). The use of grafting techniques, minigrafts and autologous cultured melanocytes is interesting but may be limited by Koebner Phenomenon (Falabella, 1988 and 1989, Hatchome et al., 1988 and Lerner et al., 1987).
NB-UVB phototherapy is widely used and produces good clinical results. Narrow band fluorescent tubes (Philips TL-01/100W) with an emission spectrum of 310-315 nm and a maximum wavelength of 311 nm are used. Treatment frequency is 2-3 times weekly, but never on consecutive days. This treatment can be safely used in children, pregnant women and lactating women. Short-term adverse effects include pruritus and xerosis. Several studies have demonstrated the effectiveness of NB-UVB therapy as a monotherapy. Oral vitamin E as an antioxidant may represent a valuable adjuvant therapy, preventing lipid peroxidation in the cellular membrane of melanocytes and increasing the effectiveness of NB-UVB therapy (Elgoweini and Nour El Din, 2009).