: Upon re-exposure, allergens cross-link IgE on the surface of mast cells, causing degranulation and the release of inflammatory mediators like histamine and leukotrienes. 2. The Atopic March

Atopy typically follows a predictable chronological progression:

: Antigen-presenting cells perceive allergens (like pollen or dust mites) as danger signals, activating TH2 or ILC2 cells.

: Sensitization through inflamed skin can lead to early-onset food allergies.