History The answers to questions with high discriminating value can quickly narrow the range of potential causes of diarrhea and help determine whether treatment is needed. Important elements of the narrative history are detailed in Fig. 122-1. Physical Examination The examination of patients for signs of dehydration provides essential information about the severity of the diarrheal illness and the need for rapid therapy. Mild dehydration is indicated by thirst, dry mouth, decreased axillary sweat, decreased urine output, and slight weight loss. Signs of moderate dehydration include an orthostatic fall in blood pressure, skin tenting, and sunken eyes (or, in infants, a. | Chapter 122. Acute Infectious Diarrheal Diseases and Bacterial Food Poisoning Part 5 History The answers to questions with high discriminating value can quickly narrow the range of potential causes of diarrhea and help determine whether treatment is needed. Important elements of the narrative history are detailed in Fig. 122-1. Physical Examination The examination of patients for signs of dehydration provides essential information about the severity of the diarrheal illness and the need for rapid therapy. Mild dehydration is indicated by thirst dry mouth decreased axillary sweat decreased urine output and slight weight loss. Signs of moderate dehydration include an orthostatic fall in blood pressure skin tenting and sunken eyes or in infants a sunken fontanelle . Signs of severe dehydration range from hypotension and tachycardia to confusion and frank shock. Diagnostic Approach After the severity of illness is assessed the clinician must distinguish between inflammatory and noninflammatory disease. Using the history and epidemiologic features of the case as guides the clinician can then rapidly evaluate the need for further efforts to define a specific etiology and for therapeutic intervention. Examination of a stool sample may supplement the narrative history. Grossly bloody or mucoid stool suggests an inflammatory process. A test for fecal leukocytes preparation of a thin smear of stool on a glass slide addition of a drop of methylene blue and examination of the wet mount can suggest inflammatory disease in patients with diarrhea although the predictive value of this test is still debated. A test for fecal lactoferrin which is a marker of fecal leukocytes is more sensitive and is available in latex agglutination and enzyme-linked immunosorbent assay formats. Causes of acute infectious diarrhea categorized as inflammatory and noninflammatory are listed in Table 122-1. Post-Diarrhea Complications Chronic complications may follow the resolution of an acute diarrheal
