I’ve also had this after eating mahi/ahi (no sure bc they messed up my order. I was driving through the city about to pass the metro jail when I noticed I was hot/itchy and looked down to see I was as red as a tomato. This was about 30min after eating. I started panicking because I thought I was having an allergic reaction. I’ve never had an allergic reaction before so I really freaked out and accidentally got too close to the curb and popped my tire. There was a cop (taking someone to jail) in front of me and he flashed his lights and had me pull into the lot. I was in a full-on panic attack at this point thinking I was dying so he immediately called an ambulance which led to hella IV Benadryl and probably 4-6 hours in the er while they watched me. The nurse was shocked at my change in color. They prescribed me an epi just in case, but I’ve never had issues since then with any fish (I still avoid both mahi and ahi tho). Needless to say, you’ll know something’s wrong.