Can the Excessive Exposure to Sunlight Lead to Vitiligo?

A large number of clinical data shows that the initial site of the white patch is mostly in the skin exposure area, and about 95% of the onset of vitiligo is related to seasonal factors, especially in late spring and early summer when it is more likely for the occurring of white patch or the increase the new white patch, of which some 7% is caused by the of sun exposure, this is because the following factors.

First of all, after sun exposure, melanocytes are hyper-functional and their tyrosinase and dopa oxidation intermediate substances are damaged, intermediate substances are an important protective mechanism, once this protective mechanism is depleted and declined, melanin will have the possibility of being destroyed;

Second of all, it may be due to the excessive production or accumulation of melanin intermediate substances that can be synthesized by the cells themselves and damage the melanocytes, thus the occurrence of white patches.

Thirdly, melanosomes on light skin are relatively light, small, and oval, and form a collection of distribution where several melanosomes wrapped together; melanosomes on dark skin are the opposite, they are dark brown, larger, spherical, and form a single type of distribution which the melanosomes do not from the collection.

Fourthly. when melanosomes are transferred from melanocytes to adjacent keratinocytes, melanosomes in light skin types are mainly found in the basal low layer and spiny cell layer of the epidermis, while melanosomes can be seen in all layers of the epidermis in dark skin types.

Fifthly, melanosomes in the keratinocyte degradation (melting, disappearance) process is also different. Most of the melanosomes in the keratinocytes of the light-colored skin species are degraded by the direct action of the lysosomes in the keratinocytes; while in the black species, the melanosomes in the keratinocytes are mainly the latter degradation pathway, in other words—diffusion to the epidermal layers, and finally separated from the epidermis with the shedding of the stratum corneum, so this is the reason why the dark-colored skin species have a darker skin color.

Sixthly, the melanin anabolism of dark skin types may be more vigorous if given the activation factor like ultraviolet light, melanin anabolism will be extremely vigorous, so it will accelerate the consumption of melanocytes; due to the vigorous melanin metabolism, the excessive accumulation of its intermediate products can in turn kill melanocytes, thus hindering the anabolism of melanocytes and the occurrence of depigmentation lesions.

Those above are the reasons why sun exposure may induce vitiligo. It is recommended that you must avoid going out in the summer when the ultraviolet rays are, and you should try to avoid sun exposure. Use the fan in summer, and before opening the air conditioner you should dry your sweat. Eat less spicy food, seafood, and food that is rich in vitamin C. Maintain peace of mind, reduce worry, and pay attention to adjusting to work and rest, thus developing good living habits.