Cross-Reactivity in Pollen Allergy

Cross-reactivity in pollen allergy occurs when the immune system reacts not only to a specific pollen but also to similar proteins found in other plants or foods. This happens because these proteins share similar structures, causing the immune system to mistakenly identify unrelated substances as threats. For example, someone allergic to birch pollen might also react to apples or carrots because their proteins are similar. Cross-reactivity explains why some people experience allergic reactions to different plants or foods related to their initial pollen allergy, even if they haven't been previously exposed to them directly.