Hi, Thanks for writing to us. From the description it seems you might be having frictional dermatitis or intertrigo. It occurs due to occlusive clothing or friction due to clothes in areas which are usually moist due to sweat like groins, axilla, infra mammary area or in between butt cheeks. Treatment involves avoiding tight clothes. Keeping the area dry and well ventilated. Applying a combination of mild steroid and antifungal cream. You may also dust the area with antifungal powder to prevent further episodes. Hope that helps. Take care.