a. Fungal sensitization: anti-fungal specific IgE
Sensitization is defined as detectable specific IgE using either skin prick tests or laboratory methods. According to current literature, the diagnosis of ABPA is possible when the level of specific IgE anti-A . fumigatus is greater than 0.35 kUA/L and probable when the value is equal to or greater than 20 kUA/L (87) (110) (103) (104).
Quantitative laboratory IgE methods allow dynamic monitoring and cross-reactivity assessment. Given the variations in fungal extract preparation and inter-method variability (Figure 3) , dynamic monitoring must rely on the same method.
Identifying the primary fungal sensitizer is an essential step because of the extensive cross-reactivity among whole fungal extracts for skin and IgE tests. It relies on the availability of molecular allergens for in vitro diagnostics, which is currently limited to Aspergillus fumigatus, A. alternata, C. herbarum , and Malassezia sympodialis .