Erosive duodenitis may develop in patients subjected to severe stress or in those consuming large quantities of alcohol. The first part of the duodenum is most susceptible to a stress-induced injury that resembles stress gastritis (see Chapter 4). The duodenum appears diffusely hemorrhagic and reddened, usually in conjunction with similar changes in the stomach (Fig. 6.82). Bleeding may be present. Erosive duodenitis begins as areas of localized interstitial edema (Fig. 6.83). These evolve with red cell extravasation and the development of erosions and full-blown ulcers. Ulcers are particularly prone to develop in situations of marked stress. Early enterocyte damage consists of cytoplasmic vacuolization with eventual epithelial loss. Enterocytes contain enlarged, hyperchromatic nuclei with prominent nucleoli, syncytial changes, and cytoplasmic tufting. The villi degenerate and the epithelium becomes mucin depleted and cuboidal in shape. The villi shorten and the crypts become hyperplastic to accommodate for the cell loss. The crypt:villus ratio approaches 1:1. Neutrophils, lymphocytes, plasma cells, and sometimes eosinophils infiltrate the mucosa and the lamina propria (Fig. 6.84). Eventually, the inflammation progresses to crypt abscesses (Fig. 6.85). The stroma may exhibit prominent telangiectasia. One may also see prominent lymphoid follicles. Often, it is very difficult to distinguish the nonspecific effects of stress duodenitis from those of peptic duodenitis.