Vascular Changes: One of the hallmark features of anaphylactic shock is increased vascular permeability. This leads to extravasation of fluids into the surrounding tissues, which can be observed histologically as tissue edema. Endothelial cells lining the blood vessels may appear disrupted or swollen. Infiltration of Immune Cells: Another important feature is the infiltration of various immune cells such as eosinophils, neutrophils, and lymphocytes. These cells can be identified in tissue sections stained with hematoxylin and eosin (H&E) and may appear around blood vessels and within the interstitial spaces.
