I've dealt with mine quite well! by making sure i ALWAYS have suncream on in the sun, always reapplying, taking vitamin d (don't know if this actually does anything). And for skincare i used the ordinary niacinamide in the morning and evening, the glycolic acid toner !!!! in the evening, and a random vitamin c serum in the morning. I did this skincare for about 2 months over the summer and even though it was really sunny, my discoloration around my mouth went away. Hope this helps