Your beard is like a condominium for filth and disease
I have had staph on my face and had to go to the emergency room for that. And had it on several other parts of the body that did not result in the emergency room. If you grapple, you will eventually get it. (For note I have never picked it up at my academy... Always from this other guy in town's place. Staph nasty)
Also have had t3h ringworm. I kill it with bleach. One application for 3 minutes (Soak a cotton ball or wash cloth and hold it there) It makes a light chemical burn, but fixes the worm with little to no trouble in one application. (I do a follow up after 2 weeks to kill any spores)
I also got flesh-eating mites when I borrowed a judo gi from the local college judo club so I could play with them one night. That is BY FAR the worst thing ever. I was miserable for 5 days before I went to the doctor. They itched day and night and it was worse at night... much worse (on my thighs, groin, face, neck, arms, and abdomen). Went there and was give a cream that killed them with one application. Here is the bad part... It continued to itch for three weeks while the dead mites, their feces, and cast off skin particles worked their way to the surface and out of my body.
I shower AS SOON AS I GET HOME after each class and don;t wear a beard or anything of the like. I roll in a rashguard to protect more of my skin. So what can I say... The life of the grappler sucks =P