What Causes Appearance Of Bump Under The Nose When In Contact With Water?

Hi,Everytime I go for a swim (regardless of ocean or pool), I end up with a red mark (not a rash) on the little bump under my nose. It doesn t hurt or itch, but it is almost every time I am in the water. It also happens regardless of whether I am training or just chilling out in the water. What could it be?Thanks