Can hives look like pimples?

My 1 year old has the flu. He is on tamiflu. And he just developed these huge blister like looking welts mainly on his tush but also on his legs and one here or there on his hand etc.

I dont think it looks like chicken pox as there isnt any on his stomach or back... wth could this be? I was just at the dr Saturday when he was diagnosed with the flu. Will be calling jn to his dr tomorrow about the rash and going in. But i dont know what to do. I have a 3 week old. Ive been really careful with purel not letting him breathe on me etc. Could this be hives?