It could be from breathing through your mouth due to nasal blockage or it could be a little fungal infection. It's easy to get a little fungal thing going on there from moisture. I would put a little Lotrimin on it personally and see if it goes away. Full treatment takes 2 weeks, so follow the directions on the tube. It doesn't matter if the tube says athlete's foot or jock itch; fungus is fungus.
I've been using all sorts of fungal infection over the counter creams , tea tree oil, gatlic and ACV it hasn't disappeared yet I've been really self cautious and going into a depressed state I'm a social butterfly and have been home for about a month due to this rash please help what else can be done???
I have had the same problem for over 3 years and got really self conscious about it. I found my eczema cream from when I was younger and applied it to my philtrum and it healed in one day. I was so amazed. The cream is called mometasone furoate cream. It is prescribed to me. Hope this helps for anyone that comes across this post!!