Cross-reactivity is a key concept in understanding food allergies and intolerances.

It refers to a situation where the proteins in one food are similar enough to the proteins in another food that your immune system reacts to both.

Imagine your immune system as a security guard, identifying and neutralizing intruders. In some cases, it gets confused between different proteins because of their similarities, causing it to react even when it shouldn't.

A common example is Oral Allergy Syndrome (OAS). Many people allergic to birch pollen can also develop reactions to apples. This happens because the proteins in apples closely resemble those in birch pollen, leading your immune system to treat apple proteins as if they were harmful birch pollen proteins (Ahammer et al., 2017; Kinaciyan et al., 2015; Kaeswurm et al., 2023).

This cross-reactivity can occur between allergens from different sources, such as animal dander and milk proteins (Schoos et al., 2021).

As well, if you're allergic to latex, you may also react to bananas, avocados, kiwis, or chestnuts due to the similarity in their proteins (David et al., 2017; Pradubpongsa & Kanechorn-Na-Ayuthaya, 2016; Parisi et al., 2021; Jalil et al., 2021; Risenga et al., 2013; Worm et al., 2014).

Cross-reactivity is not limited to food allergies. In the context of food intolerances, such as celiac disease, people intolerant to gluten can sometimes react to proteins in foods like oats because they resemble gluten (Marasco et al., 2020; Dvořáček et al., 2022).

However, remember that not everyone will experience cross-reactivity, and reactions can vary widely in severity.

If you suspect you have a food allergy or intolerance, it's essential to consult a healthcare professional for accurate diagnosis and guidance.

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