Some relevant clinical statistic indicate that most of vitiligo patients before this disease or worsen have the history of the sunburn. Because of when the sunshine irradiate perpendicularly to the ground, the irradiation strength is strong. The skin easily to have inflammation after the severe sun burning, it will cause the melancytes damaged and loss the ability to produce melanin. So the depigmented macule will appear on the superficial of skin. So many of the vitiligo patients afraid to light, they are worried about summer coming.
We know that UV ray from sunshine can make the skin color become deeper, for the UV ray can stimulate the activity of the tyrosinase that is necessary for enzyme forming melanin. The sunshine can accelerate the tyrosinase to transfer to dopa, etc. this will accelerate the metabolism of melancytes. So usually sunshine can promote the formation of the melanin. So the regular expose under sunshine can promote the formation of the melanin, the melanin which have been formed will transfer to every layers epidermis. And make the skin color deep beneficial to the recovery of vitiligo.
However too mush sunshine is not good for the recovery of the vitiligo. The UV rays will inhibit the substance forming, that substance can form mercapto, mercapto will inhibit the activity of the tyrosinase, and it would not beneficial to the metabolic of melancytes.
So the vitiligo patients should try not exposed to hard light, but the patients can accept the appropriate long wave UV light. The amount of UV light is determined by the patient’s skin condition. So the patients can adjust the sunshine time according to the different seasons. Such as the autumn, winter, and the beginning of spring should choose the around the noon.