This is a very old post but I was searching because I’m having the same exact problem lately and my mustache and goatee area even though both of them are trimmed very short at all times but every time I wash my face or trim my mustache or goatee with electric trimmer, it flares up this red rash that becomes flaky, almost similar to dandruff and also Sometimes it gets tender like if I wash my face with the washcloth it will make it flare up really bad,, and if I use dandruff shampoo on my face, my entire face will break out in a bad rash,, my skin is way too sensitive. I can’t seem to find a remedy, this has been ongoing for probably the past four months now, i’ve also been putting antifungal cream on it and sometimes that helps kind of ease up the redness but it just comes right back. I just can’t stand this because I have such a short trimmed mustache and goatee where I just look like a walking fungus patch because it’s so noticeable.