Methods: A unique combination of state-of-the-art methods will be applied, including single-cell RNA sequencing and receptor profiling, proteomics, determination of the microbial composition, recombinant antibody screening and disease modelling in cell cultures. Expected results: The investigators expect for the first time to discern the drivers of local IgE production in LOA and uncover the immunological pathways leading to local IgE production in AA and LOA. Moreover, the investigators will obtain insights into the role of Dupilumab in modulation mechanisms. Impact: If successful, these insights will answer a long standing, unresolved question in type 2 disease and might aid in the development of novel directed therapeutics for AA and LOA.