【正文】 spital for further evaluation and lab investigation. L umbar puncture revealed normal opening pressure, and CSF examination showed WBCs 45/μL, protein 78 mg/μl glucose 64 mg/μl. Bacterial, fungal, and viral cultures of CSF were all negative. Based on results of a positron emission tomography(PET) scan and serology tests, the the patient was empirically started on therapy.病例十九A 41yearold man presented with a 4month history of worsening abdominal pain, diarrhea, nausea, and vomiting with blood. His abdominal pain was mainly in his right upper quadrant.The man had recently immigrated to the United States from Kenya.PHYSICAL EXAMINATIONVS: T 37℃, P 110/min, R16/min, BP 136/80mmHgPE:An illappearing male in mild distress due to abdominal pain。 enlargement of the liver and spleen, with mild tenderness, was noted.LABORATORY STUDIESBloodHematocrit: 32%WBC: 9400/μLDifferential: 54% PMNs, 20% lymphs, 18% eosinophilsSerum chemistries: AST 78 U/L, ALT 92 U/L, bilirubin μmol/L, albumin g/dLImagingAbdominal ultrasound showed enlarged liver and spleen with evidence of portal hypertension.Diagnostic WorkUpTable 521 lists the likely causes of the man’s illness (differential diagnosis). Diarrheal stool specimens may be positive for blood. Routine enteric investigation may be a good start to rule out enteric bacterial causes of diarrhea。 however, further investigation for specific microbiologic diagnosis may includel Blood culture. Can aid in ruling out typhoid fever or other bloodborne agents that cause febrile illnessl Ova and parasite examination of stool TABLE 521 Differential Diagnosis and Rationale for Inclusion (consideration)Dysentery syndrome Entamoeba histolytica Shigella dysenteriaeInfectious gastroenteritis (Salmonella)Inflammatory bowel diseaseSchistosomiasisTyphoid feverViral hepatitisRationale: In a person from a superendemic area, infectious gastroenteritis must always be considered. Diarrhea is very mon and is not very useful by itself for narrowing the differential diagnosis. Other symptoms, such as hepatosplenomegaly, are helpful because most mon causes of diarrhea do not lead to this plication. Schitosomiasis is one of the causes that should be considered。 it is very mon in endemic areas. Typhoid fever is always a consideration in patients with fever and abdominal pain who have recently been in a developing country. Acute viral hepatitis should be considered in patients who have fever and rightupperquadrant pain, although hematemesis would not be expected.COURSEStool specimens and blood cultures were obtained. The patient was started on appropriate empirical therepy. Characteristic fluke eggs were identified in the concentrated stool after trichromestaining.病例二十A 42yearold man presented to a clinic with plaints of 3 weeks of worsening diarrhea, abdominal pain, and fevers. He had noticed an itchy rash over his buttocks and groin area for the past 2 weeks. A 15lb weight loss was also noted. A month before his symptoms started, he had returned from a 3month trip to El Salvador, where he worked in a rural area.PYSICAL EXAMINATIONVS: T ℃, P 84/min, R 16/min, BP 112/62 mmHgPE: An erythematous maculopapular rash was present on his groin and buttock area.LABORATORY STUDIES BloodHematocrit: 43%WBC: 10,200/μLDifferential: 52% PMNs, 15% lymphs, 24% eosinophilsSerum chemistries: NormalImagingNo imaging studies were done Diagnostic WorkupTable 501 lists the likely causes of illness (differential diagnosis). Stool should be examined for leukocytes. Investigational approach may includel Enteric (bacterial) culturesl Microscopic (ova and parasite) examinationl Toxin testing for Clostridium difficilel In failed investigation, colonic biopsy and histopathology to differentiate idiopathic ulcerative colitis and Crohn diseaseTable 501 Differential Diagnosis and Rationale for Inclusion (consideration)Amebic dysenteryBacillary dysenteryClostridium difficile colitisCrohn diseaseHelminth infectionHookwormsStrongyloides stercoralisAscaris lumbricoidesTrichuris trichiuraRationale: The unique feature regarding this case is the significant degree of eosinophilia. This limits the differential essentially to parasitic infections. Other etiologies can also be considered if initial workup is negative, although these would be rare in the presence eosinophilia. Noninfectious causes may be considered if infection has been ruled out.COURSEThe patient was admitted to the hospital. A stool sample was sent to the state public health laboratory, where ova and parasite examination revealed nematode larvae.ETIOLOGYStrongyloides stercoralis (strongyloidiasis)19