What would cause itching and red bumps if it's not chicken poxs?

Many possible causes: There are a number of diseases that cause 'red bumps', including herpes, contact dermatitis, bacterial infections, and many more. Have your primary care doctor or a dermatologist take a look if the rash does not resolve on its own, significantly bothers you, or recurs.

Many things: There are many different types of rash that can be itchy and bumpy. In order to know exactly what the diagnosis is, you need to be seen by a doctor. Rashes cannot be diagnosed without inspection of the skin. I recommend you see your doctor to determine the possible cause and best treatment for your rash.