I Am Extremely Itchy From Just Above The Elbow Down

I am extremely itchy from just above the elbow down to my wrists on the top parts of both my arms. I cannot determine if it is an allergy or some kind of eczema/pruritus. The sensation is like an uncomfortable pinchy tingly prickle that cannot go away. when scratched I feel the relief, but then itching spreads to other areas of the arm and cannot be isolated. Ice packs are the only thing that stop the pain/itching. I have had this for 16 months.