What Do Rashes On Crease Of Legs Indicate?

Hi I'm a 20 yr old female and I'm getting these rashes that feel like razor burn in the crease of my legs. I get chaffing from time to time but this spot is higher than where I normally Chaf. It usually goes away in a day or so and I usually put Vaseline on it. It doesn't smell or blister but it hurts from being rubbed. What is this?!