Poorly toddler with rash

[Rathyma]

I'm just wondering what you all think of this...
My DS has had a cold for about 2 weeks (as have the rest of us) and started with a fever on Tuesday. He was intermittently really cold then really hot. He has been having regular Nurofen since and occasionally Calpol too when he's feeling really rough. He saw the Dr on Thursday who said one ear drum was bulging slightly, his throat looked a bit sore etc and prescribed penicillin.
He hasn't improved since. He constantly says he's tired, is off his food and is a little unsteady on his feet. This morning he has spots on his face that look like chicken pox and has what looks like a general viral rash all over.
Does anyone have any similar experiences? I'm probably going to end up taking him to the Dr again in the morning but I don't know what else they could do?!
Could it be chicken pox?
Thanks all.

Chicken pox tend to look like scabby blisters, sounds like it could be a viral rash, if you're concerned definitely go back to your doctor, I've been there a few times and I think it's better to be over cautious.

Could the spots and rash be a reaction to the penicillin?

I had wondered about the penicillin too, but he hasn't had vomiting or diarrhoea which I think are also common signs of a reaction to it.
He's actually much better this morning and the spots and rash are fading. I agree, I think it must have just been a viral rash.
Flipping kids! Haha
Thanks for your replies. x