Hi, I can understand your concern for the problem. This is due to activity of melanocytes which causes deep pigmentation on aforesaid areas. Melanocytes are the color producing cells of skin. This is genetically determined in majority of cases and varies form person to person accordingly. The most important part in treatment is by lightening agents such as Kojic acid or azelaic acid cream application which you can use under dermatological guidance. Hydroquinone can also be used but in my series of patients I prefer using Kojic acid or azelaic acid cream. The most important thing is sun protection by all measures. Eat healthy diet containing lot of Vitamin A and Vitamin C. Do not try applying over the counter products and Mometasone too as these can further aggravate the situation. Mometasone in particular is a steoid which can cause skin atrophy and hair-growth. Protect yourself form direct sunlight. Use a good sunscreen on exposed area for 2-3 times and drink plenty of liquids everyday. All the best.