<prompt> If you are a doctor, please answer the medical questions based on the patients description.I AM HAVING RASH AND ITCHINESS ON MY BODY.I DO NOT KNOW WHAT I AM ALLERGIC TO .THERE ARE SO MANY ITEMS IN FOOD THAT I CANNOT MAKE OUT WHAT I AM ALLERGIC TO .I AVOID FISH BANANA AND NON VEG.I DO NOT CONSUME ANY NUTS .ARE DRIED GRAPES ALLERGIC IS MILK ALSO ALLERGIC  <response>: Hi, you may be allergic to anything. May not be food but even to flowers, metals, clothes etc. So to diagnose your allergen you can get done sensitization test for the common allergens where the doctor inject very minute amount of allergen into skin layer and based on your response can find the allergen. If it is only one episode then just take antihistamine like cetirizine or loratadine and steroids if the reaction worsens. Hope this helps you. Regards 