What is wrong with my skin?

I am 20 years old and suffer from scrotal and thigh-fold itching since 5 to 6 months. I was prescribed anti-histaminics, which gave me temporary relief but I need to take them regularly like twice a week. I took Cetrizine as it is not a sedative. I do wear a lot of tight jeans and need to work a lot as I am a college going student. I have not developed any lesions on my skin. The itching gets aggravated at night, which is a torture. Please suggest a permanent solution for it.