If you have any of these fun symptoms:
Soon after or seemingly correlated with eating any of these fun foods:
Then you may have a fun & flirty citrus allergy!
Do your best to eliminate all other factors, of course. I'd say 'ask your doctor', but this isn't a very well-known allergy. Many doctors I've known don't realize it can exist, because citric acid is a byproduct of cellular metabolism-- except that metabolism stays inside the cell, and never encounters the body's immune system. The citric acid cycle is unrelated to a citrus allergy.
You may be allergic to the small amounts of mold left in factory-produced additive citrus acid (the kind that's usually added to sour seasonings), allergic to citrus fruits specifically, or simply allergic to citric acid, period. (I fall in the latter category). You may be sensitive to very large amounts (eating several oranges) or very small (eating a single RedVine), or very small (breathing where someone has made koolaid recently). (I fall in the RedVine category.)
It's worth mentioning that grapefruit has a compound in it that interferes with metabolism of a great deal of medications, so if you're just reading for fun, and happen to be taking medications for anything regularly, read up on that; you can end up poisoning yourself combining medications and grapefruit as the medication won't filter out as quickly as it should.
I write this to raise awareness of this allergy, as it sucks, since citric acid is in damn near everything. I can't blame anyone; it tastes delicious. I grew up eating tangerines off the tree; I know exactly how delicious they are, and crave them all the time. But hey-- surprise, allergy.
Gotchas to look out for:
Fruity things surprisingly low in citric acid, for your cravings:
I AM NOT VOUCHING FOR THESE FOODS' SAFETY. I, personally, did not have a reaction to them. If your citric allergy is mild, and doesn't cause anaphylaxis, then you might gain from experimenting with them as well.