I also developed several food intolerances with Long COVID. I did the elimination diet for several weeks and found cream gave me painful swollen fingers, eye hemorrhage, and swollen eyes, wheat & gluten & gluten free bread made me constipated with raised red rash on face, mild petechiae on legs and arms, eyes swollen, red and dry, joint pain, and a high tight bloated abdomen, sugar gave me swollen eyes, red cheeks, and much more painful joints, corn gave me red cheeks, dry eyes and increased joint pain), and cheese with mold like blue cheese turned by cheeks bright red and hot.

I have not been able to find a doc who treats mast cell activation but I believe that is what I have.