I'd be very reluctant to give the antibiotics. They are very over prescribed these days and then when our LOs truly need them, their bodies have already built up resistance to the drugs and have no effect.
Our GP is quite laid back and his general attitude with most things is to give everything 1-2 weeks to improve on it's own before attempting to treat it with drugs of any nature. Especially if your LO seems well in himself otherwise, I'd be inclined to do the same. I'm also surprised that he was prescribed steroid cream for his face - that's the one area that is usually avoided because the skin is particularly thin...
How's he doing?