The necrotic epithelium becomes embedded in exuding fibrin and red and white cells，so that a grayish pseudomembrane is formed-commonly over the tonsils，pharynx or larynx.

坏死的上皮胞被纤维、胞和胞凝聚在成灰色的假膜，通常覆盖在扁桃腺、咽或喉。