Rashes?? Or something else?

My son seems to have some sort of rash? It started from his face. And now it has spread to his body and some on his arms and thighs. I doubt its an allergy thing because he woke up with rashes on his face this afternoon. He was fine and just recovered from a fever yesterday. Any mummies have any clue?? Should I just bring him to the polyclinic, or straight to A&E?? I'm hoping its not serious and it will go away soon. #pleasehelp #advicepls