For The Last 2 Weeks, I Have Been Experiencing Itching

For the last 2 weeks, I have been experiencing itching problem. It starts in the evening, especially after dinner. I am on high protein and low carb diet. I also take whey isolate in the morning after work out. I eat chicken breast, egss, paneer, veggies, apple, sprout, brown rice, white rice. More or less my die and food choice remain same. I get the itchy feeling all over my skin and then I need to scrub it with my fingers. Then it becomes red. It goes on for 1-2 hours and then it fades. I do not have any skin problem. Nothing happens during the day. One thing I want to metion is that I have been having the same diet, same whey isolate for years but on / off. This is the first time I have started experiencing this problem and it is not going away. I am losing my sleep 'coz of this problem. I took a full blood test and the protein content is on the higher side. Otherwsie, report was normal.