Impact Statement
We showed for the first time that barley allergy associated with wheat allergy is caused by cross-reactivity from wheat. In this study, we found that wheat OIT increased the symptom-inducing threshold of barley allergy. Although the cross-reactive proteins between wheat and barley were not identified from the results of immunoblotting inhibition, it is expected that the mechanisms of cross-antigenicity of wheat and barley will be clarified in the future.