The main source of histamine during acute inflammation is mast cells. These cells are strategically located near blood vessels and mucosal surfaces, allowing rapid release of histamine upon activation. Histamine increases vascular permeability and vasodilation, leading to redness, swelling, and recruitment of immune cells to the injury site. Neutrophils, macrophages, and eosinophils do not store significant histamine and thus are not primary contributors to its early release in inflammation. Understanding this is crucial for managing allergic and inflammatory responses in clinical practice.

Reference: Robbins Basic Pathology, Kumar, Abbas, Aster, 10th Edition.