Right Between The Side Of My Abdomen And The Top

Right between the side of my abdomen and the top of my thigh (on one side only) i have a very sensitive, topical, skin irritation----it's probably about four inches long and is very red and follows the contour of the crevice that it's in. I don't feel any pain outside of the skin irritation, but in retrospect I do remember a sharp pain to my groin two days ago after carrying a bunch of luggage down several flights of stairs. Again, my groin feels fine and my leg is not stiff, but the skin itself does feel quite irritated. I am about 75lbs overweight and was doing a lot of driving, so I wonder if it's just a skin irritation from driving and having my legs kind of stuck together?