Lots of clinical data show that vitiligo will first appear on the exposure positions on human skin. About 95% vitiligo has relation with season, especially during the end of spring and the beginning of summer, vitiligo is easy to appear and increase new white spots. About 7% vitiligo will appear after exposure in the sunlight. This is because :
First, after exposure in the sunlight, melanophore function will get hyperfunction. Tyrosinase and dopamine oxidation intermediate material will be destroyed. The intermediate material is a kind of important protection mechanism. Once this protection mechanism consume and decline, melanin will be easy to be destroyed.
Second, if the intermediate material to synthesize melanin excessively produce and accumulate, these material will damage melanophore and then induce white spots.
(1) Light-skinned people have relative light melanin, the area will is small and is oval, distributing like the set type, which means several melanin will gather together. And deep-skinned people have the opposite condition. Their melanin has dark color, large area and like a sphere, distributing single, which means their melanin existing individually.
(2) When melanosomes transfer from melanophore to neighboring keratinocyte, the light-skinned people’ melanosomes mainly exist in the base lower epidermis and Prickle cell layer. And deep-color people’ melanosomes can exist in every skin layers.
(3) The melanosomes degradation process is also different in the keratinocyte. Light-skinned people melanosomes will be mostly directly affected by the lysosome in keratinocyte. And for deep-skinned people, their melanosomes in keratinocyte will have this degradation process, which means diffusing to every layers in the epidermis, finally, these melanosomes will separate with epidermis with the drop of cuticle. This is why deep-skinned people have darker skin color.
(4) Deep-skinned color people have more exuberant melanin synthesis and metabolism. Once ultraviolet ray activate melanin, melanin’ synthesis and metabolism will be very exuberant, thus accelerating the consumption of melanophore. Because of exuberant melanin metabolism, the intermediate products will kill melanophore in turn, thus stopping melanophore’ synthesis and metabolism.
We suggest people avoid direct strong sunlight and the strong ultraviolet ray in summer. In summer, you should dry your sweat before using fan. In daily life, eat less spicy food, seafood and food rich in vitamin C. Keep good spirit state and cultivate a good living habit.