IGHE and breast angiosarcoma: Also, we found that there were significant differences in fractional exhaled nitric oxide (FeNO), forced expiratory volume in 1s (FEV1)%, FEV1/ forced vital capacity (FVC)%, immunoglobulin E (IgE), serum eosinophils, and serum neutrophils between mild‐to‐moderate BA group and severe BA group.