My wife's back "upper part" is almost full of itchy bumps, she just got them suddenly, also a big spot on her chest and some red bumps on her face.

Hives: Thisis an allergic reaction most likely. As long as she has no breathing problems or loss of blood pressure these are hives. You can try bendryl but you will need to see your doctor. Look for exposures like a new medication, a food, now fabrices, new chemical exposures, infection = the list is very long and often we can not discover the cause. We call this urticaria.