What Causes Itchy Skin Along With Numbness In Upper Right Back?

Skin itching and numb in certain areas...mainly localized on small area on upper right back and area on back of right arm. Almost feels like hives or rash but itchy areas are read and have a few small bumps but no puss. Not sure if it s cold weather/dry skin, allergic reaction to something, stress or some other cause. Any thoughts?