hi. Thanks for posting in HCM Seems that you are suffering from Intertrigo which is inflammation of body folds. Body folds like groin, axilla, sub-mammary area, gluteal cleft are prone to intertrigo because sweat gets trapped in these folds and the skin gets macerated. So when the skin folds rub against each other during walking and running the already delicate skin (macerated) gets inflammed and sore. Sometimes this is superimposed by a fungal infection by candida which cause itching and more inflammation. I would advice that you keep the area dry. You can use an Antifungal dusting powder in that region. I would advice that you consult a dermatologist who might want to give you topical steroid+antifungal cream preparations for a few days. Take an oral antihistamine like cetrizine for itch relief. Take care regards