Dogface Puffer disease??

[krissyfish20]

Hi!
My dogface puffer has something on him that I'm not quite sure what it is. He has them on his head and side of the base of his tail. They look like little clusters of pimples or cysts or something, and don't seem to be spreading at all. Has anyone ever experienced this, or know what kind of treatment I can use? Even though they aren't spreading I don't want it to progress into anything more.
Thanks