Yes take him to the vet. He's got a very specific type of mite that attacks the ears, nose and feet. He'll need Revolution (selamectin) or ivermectin to treat them.
"Notoedres muris (also termed the ear mange mite) burrows into skin, and can present as yellowish crusty appearing warts on edges of ears and nose, or can appear on other extremities as reddened bumps. Both of these are not often seen in the domestic pet rat."