Is Azithromycin Sufficient For The Treatment Of Fever, Cold, Cough, Congestion And Pink?

My seven year old son has been sick with a nasty case of the crud.... Fever, cold and congestion and pink eye. The dr put him on azithromycin and antibiotic eye drops for the pink eye. He is on day 3 of both antibiotics. His fever has been gone since yesterday but he still has congestion and cough. This evening he started breaking out in hives on his stomach and legs and they are spreading and itchy. He has been on azithromycin before and no reaction ( although he has never been on the eye drops) what could this be from?