When I scratch I get hives or even lean my head on my arm I get a rash on my face. The doctor told me it was eczema but I don't think it's that?

Dermatographia. You have a condition known as dermatographia the cause of which is unknown. It is known as skin writing and affects about five percent of people. The phenomenon lasts about thirty minutes before disappearing. Sometimes, Benadryl (diphenhydramine) is needed.