I have the same problem. It’s usually sour patch kids that do it to me, and that it because of those sour-stuff crystals. Warheads are smooth so I don’t know why, but that is interesting.
I dunno man. I have never heard of that problem. Two resolutions though 1. Stop eating something if you bleed from it 2. See a doc if you dont like suggestion one
Ascorbic acid? It’s sometimes used to make things have a sour taste. At the markets in the US, it’s packaged under the name Fruit Fresh and is used when prepping jams and the like. You can also use it in guacamole to prevent it from browning instead of fresh lemon or lime. You could be sensitive to it when it is concentrated like that.