Histological examination of tissues can be performed using various staining techniques. Hematoxylin and eosin (H&E) staining is commonly used to observe general tissue architecture and cellular details. Immunohistochemistry can be employed to identify specific cell types and the presence of specific mediators such as histamine and tryptase. Electron microscopy can be used to observe ultrastructural changes in cells, such as degranulation of mast cells and endothelial cell alterations.