I just got a rash all over my body, itchy. Not taking any meds though?

Nonspecific. Nothing is less specific than a generalized itchy rash. It could be a virus, or an allergic reaction, something you ate, something you inhaled, or many other things. You say you're not taking any medicines; are you taking vitamins or other supplements? They can cause rashes too. A dermatologist will either identify it by looking at it, or run tests to narrow down the possibilities.

Related Questions

Have a red itchy skin rash on belly and arms?

Rash. Rashes are difficult to diagnose without being seen. Is it flat, pebbly, blistery? How long present? How large an area involved? Any contact with poison ivy personally or a pet? Any exposure to ticks? Any exposure to measles/chickenpox/etc? See pcp for evaluation & treatment of rash. Read more...
Rash. This can't be diagnosed with the information that is available. A history, physical examination & other studies may be needed to determine cause/causes. Once accurately assessed a treatment plan can be developed. Read more...