IGHE and cystic fibrosis: Diagnosis of ABPA relies on a combination of factors including but not limited to: the presence of a predisposing condition i.e. CF or asthma, peripheral blood eosinophilia (≥500 cells/mm3), a positive Aspergillus skin test, which reveals immediate cutaneous hypersensitivity to A. fumigatus antigens and elevated total serum IgE levels (≥417 IU/mL) [94].