Hypersensitivity

The grounding supports antigen-driven reactions as the immediate cause, with subsequent exposure to a sensitizing antigen triggering pathology. It also links allergic hypersensitivity to disrupted epithelial integrity, alarmin signaling, and altered microbiota-mediated immune tolerance, but does not support a single universal cause.

The supplied reviews describe hypersensitivity/allergy as involving type 2 immunity, beginning with epithelial and innate immune activation and progressing to adaptive T- and B-cell responses. Type 2 cytokines promote Th2 development, eosinophil recruitment, and IgE production; IgE then binds mast cells and basophils, which degranulate on re-exposure to allergen. Macrophage polarization and immune tolerance mechanisms are also implicated in inflammatory balance.

Supported risk factors include early-life antibiotic use, altered gastrointestinal microbiota, and dietary differences associated with industrialized settings. The grounding also supports prior sensitization to allergens and exposure to allergens such as pollens, dust mites, and hymenoptera venom in allergic disease contexts.

Allergen immunotherapy is described as a cornerstone treatment for allergic children, with subcutaneous and sublingual administration as the main modalities. The grounding also supports broader allergy-directed therapy targeting IgE, cytokine, and alarmin pathways, but does not provide specific drug names or regimens.