Can Using Tide With Febreeze Be Causing Welts On Torso?

My son has a large oval welt on the side of his torso and a much smaller area that looks irritated on the other side of torso. Recently he broke out to what seemed to be a heat irritation on his inner thighs, but that cleared up. Now he has this welt. No itiching or discomfort. He was shorts with elastic waistband which I feel may be aggrevating the welt even more. I use Tide detergent but recently used Tide with Febreeze. Not sure if that is irritating him coupled with elastic. Is that possible?