Hello,
I cannot confirm anything without examnation but it can be intertrigo,
heat rash or contact dermatitis. An intertrigo is an inflammation (
rash) of the body folds.It most commonly occurs due to bacterial,viral or fungal infection. An intertrigo usually appears red and raw-looking, and may also itch, ooze, and be sore.
Pls keep the area clean and apply some topical antiseptics. Also wear loose-fitting cotton clothing and use an antibacterial soap or mild soap like dove.