Hi Tanning happens sure to the increased melanin pigment on the skin. It happens usually dye to exposure to UV rays of the sun. It may also be the result of some cosmetics used on the skin or some medications or hormonal. Avoid direct exposure to strong sun light by covering your face or using an umbrella or such thing You can use good sun screen cream or lotion to reduce the effect of UV rays. If need be & possible, you can visit our clinic. Regards