Random rash, what could it be?

since it is summer i have been wearing shorts a lot. i have been outside a bit and got some mosquito bites on my legs, nothing out of the ordinary. but i noticed i got a few more than normal on the back of my thighs and around my butt cheeks. they have irritated me pretty bad and my mom is starting to think its not bites but something else? any ideas? or how to find out what they could be? thank you for your time.