Following the first contact between the body and an allergen (pollen, mites, cat fur, latex proteins, etc.), antigen-presenting cells ( dendritic cells, macrophages) stimulate B- and T-cells. These cells communicate between each other using membrane proteins but also mediators they produce, such as interleukins (IL1, Il2, etc.). The plasmocytes deriving from this cascade of reactions then produce IgE specific to the original allergen. This initial phase, known as 'allergy induction', concludes with IgE binding to basophiles and mast cells.