external parasite?

Hello,

I have had this Midas Blenny for 8 days now. For the last few days he has been crashing and rubbing in the sand. I believe this is called "glancing" and is associated with external parasites. This morning, I noticed a red infected looking mark above his right eye. I don't see any white spots on his body (besides the sand stuck to him from crashing in the sand bed).

I have only had a salt water aquarium for 6 months now and this is the first fish that has been sick so I am a little unsure how to treat him? I am isolating him this evening in a quarantine tank.

Any ideas on what he has? What sort of medicine should I use?

Thanks!