Cures: The only known remedy for this affliction is to seek out a mirror immediately. The word of friends or family will do nothing to assuage the mounting panic the sufferer displays, which will generally manifest itself in frantic and overly-frequent rubbing of the nose or nostril(s)
2nd person: "I don't see anything. You must be suffering from Mucophobia."
1st person: "Did you see a mirror in the bathroom?"