Hi. Greetings. This could be pityriasis versicolor. However you need to get this confirmed by examination by a dermatologist. Or you could send in your pics. This Fungal infection is quite common. This is often related to tight clothing, excess sweating and accumulation of moisture. You'll need to keep the area dry, wear lose clothing. DO NOT USE OVER THE COUNTER CREAMS LIKE BETNOVATE GM OR PAN DERM OR QUADRIDERM... this will only prolong the infection. Hope this helps.