Yes, Sometimes chicken pox will have "a second run". Although not as contagious as the original. Be sure the poxs are simply not reinfected original pox-marks.
The bumps returning could be a sign of trouble. Some people's immune systems have a hard time fighting off the infetion. He may need a trip to the doctor.
No it is not coming back after 5 days, it is just spreading and not getting better. You need to get some more medicine and call your doctor as soon as possible.
