Allergy

Patient: Dear Dr…I am 28 boy. I have skin allergy more than three years. I have been using anti histamine medicine every day since then. I have used different type of tablets but still not work. when it comes to me all my body become red and itch me. some of the doctors said that I have dermographsim and some of them said no it is just from food or some thing like that. However, I have tried to change my food each month but not work.please helpI do not know what to do

Symptoms: itching, red skin, even my eyes itching,

Doctor: