Hello, Thanks for the query. you might have developed a fungal infection, It is called as tinea cruris. It is common in folds of skin like butt crack. However it can occur on other parts of body as well. You need treatment with oral as well as topical antifungals. Try to keep the area dry, You can also use powder to maintain dryness. Take some anti histamine tablet also, This will give you relief from itch. Please meet a dermatologist for exact diagnosis. Let me know if you have any other doubt. you can ask a direct question to me on this forum, following the below link. http://www.healthcaremagic.com/doctors/dr-rahul-kumar/64818 Wishing you a good health. Thank you