Zkřížená alergie: co to je, jak se projevuje a co s ní

When you react to something you didn’t even think you were allergic to — like getting itchy after eating a banana even though you’re only allergic to pollen — that’s zkřížená alergie, reakce imunitního systému na podobné bílkoviny v různých látkách, které si připomínají původní alergen. Also known as křížová alergie, it happens because your body can’t tell the difference between, say, birch pollen and raw apples — they look too similar at the protein level. This isn’t just a weird coincidence. It’s a real, well-documented phenomenon that affects many people with seasonal allergies, especially those sensitive to pyl, většinou z dřevin jako berезa, ořešák nebo trávy.

If you’re allergic to pyl, přírodní látka z rostlin, která se šíří vzduchem a vyvolává rýmu, kašel nebo svědění očí, you might suddenly get mouth tingling after eating apples, carrots, or hazelnuts. That’s not a food allergy — it’s a cross-reaction. The same goes for people with celiakii, autoimunní onemocnění způsobené reakcí na lepek, které poškozuje střevo. Some find that even non-gluten foods trigger symptoms because of similar protein structures. And if you have astma, chronické onemocnění dýchacích cest, které se projevuje zúžením průdušek a obtížemi s dýcháním, cross-reactive allergens can make your attacks worse — even if you’re avoiding the obvious triggers.

It’s not just food and pollen. Latex allergies can cross-react with bananas, kiwis, or avocados. Dust mites might cross-react with shellfish. And if you’ve been told your symptoms don’t make sense — like itching after eating nuts but never having eaten them before — it’s probably not in your head. It’s your immune system getting confused. The good news? Once you know what’s causing the cross-reaction, you can adjust your diet, avoid risky combinations, and reduce flare-ups without drastic changes.

You don’t need to eliminate everything. Sometimes just cooking the food helps — heat breaks down the proteins that confuse your immune system. Raw apples? Maybe not. Baked apple pie? Usually fine. Same with carrots or celery. And if you’re unsure, a simple skin prick test can show you which proteins are triggering the mix-up.

Below you’ll find real-life guides from people who’ve been there: how to spot if your cough is from pollen or something you ate, why lepek might be linked to your asthma, how to tell if your rashes are from celiakie or a cross-reaction, and what actually helps when your body feels like it’s fighting ghosts. No fluff. Just what works.