Which factor can exacerbate hyperpigmentation?

Ultraviolet exposure is a well-documented factor that can significantly exacerbate hyperpigmentation. When the skin is exposed to UV rays from the sun, it triggers the production of melanin, the pigment responsible for skin color. This process is a protective response to prevent damage from the UV radiation. However, in individuals already prone to hyperpigmentation or discoloration, this increased melanin production can lead to uneven skin tone and the darkening of existing pigmented areas. Therefore, protecting the skin from UV exposure through the use of sunscreen and appropriate clothing is essential in managing and preventing worsened hyperpigmentation.

Other factors listed, such as low humidity, cold temperatures, and high pH levels in skincare products, do not have the same direct impact on hyperpigmentation. Low humidity and cold temperatures primarily affect skin hydration and barrier function, while high pH levels in skincare can lead to irritation rather than directly promoting melanin production.