In the case of an injection of fennel extract, mice intraperitoneally and intranasally injected with ragweed pollen, experiencing allergic rhinitis, exhibited stronger allergic responses in the oral cavity than mice intraperitoneally injected with ragweed pollen, suggesting that the former sensitization method is more appropriate for analyzing IgE cross-reactivity in murine model of OAS. This evidence concerns the gene IGHE and microphthalmia with limb anomalies.