Acute Appendicitis Mimicking Infectious Enteritis

Abstract

Objective. To verify the role of sonography in screening of acute appendicitis in patients admitted to an infectious disease unit for suspected acute infectious enteritis. Methods. One hundred eighty consecutive patients (102 male and 78 female; age range, 5-72 years; mean age, 31 years) admitted for suspected infectious enteritis or typhoid fever were prospectively studied with abdominal sonography within 48 hours after admission. None of the patients had peritoneal irritation. Forty-six patients (25%) had white blood cell counts of more than 10,000/mm 3 (range, 10,300-18,000/mm 3 ). The diagnosis of acute appendicitis was made when a detectable appendix with an anteroposterior diameter of greater than 7 mm could be seen on sonography. Results. Eleven (6%) of 180 patients had thickened appendixes (anteroposterior diameter range, 7-14 mm); 2 of them had periappendiceal abscesses. Four (36%) of 11 patients with acute appendicitis had high white blood cell counts. All sonographic diagnoses of acute appendicitis and periappendiceal abscesses were confirmed at surgery. Sonography ruled out acute appendicitis in 169 patients. In all of them, clinical and sonographic follow-up excluded the diagnosis of acute appendicitis. Normal appendixes were shown on sonography in 38 (22%) of 169 cases and were not detectable in 131 (78%) of 169. Conclusions. Sonography of the appendix is a useful method for early assessment of acute appendicitis in patients thought to have enteritis or typhoid fever.

Criteria for distinguishing the appendix from ileal segments sonographically: a different perspective

“…The normal appendix can be visualized in approximately 12-82% of patients [16,[18][19][20][21]. In inflamed appendices, this rate increases to up to 95% [22].…”

“…However, even to experienced sonographers, the normal vermiform appendix is not always visible sonographically. With conventional US imaging, a normal appendix can be clearly identified in 12-82% of cases [16,[18][19][20][21]. This rate is higher in pathologic appendices [22].…”

Infectious Enteritis

“…It has been widely shown that ultrasound may reveal a high incidence of infectious ileocecitis in patients with acute right lower quadrant pain where appendicitis is suspected (Puylaert et al 1988(Puylaert et al , 1997Tarantino et al 2003). Sonography may also reveal the features of the bowel wall useful in the differential diagnosis between infectious ileocolitis, Crohn's disease and appendicitis (Table 1).…”

“…Therefore, in individuals presenting with abdominal pain, diarrhoea and fever, or patients with acute or atypical symptoms and infants, as well as immunocompromised and elderly patients where a differential diagnosis between bacterial infectious enteritis and other acute abdominal conditions is mandatory, ultrasound can be employed to avoid unnecessary laparotomies and to avoid delay of surgery or specific therapy ( Fig. 1) (Puylaert 1994;Tarantino et al 2003).…”

Sonographic examination of the appendix in acute infectious enteritis and acute appendicitis

“…However, the symptoms of AA (fever and right lower abdominal pain) are often similar to those observed in acute infectious enteritis (AIE). [1][2][3] Early diagnosis can be difficult in cases in which the sonographic appearance of AA is not typical. Therefore, the present study assessed the ability of sonography to visualize the normal appendix in AIE compared with a control group of normal appendices and a group of patients with AA.…”