Acute appendicitis

Type Characteristics
Simple acute Mild hyperemia, edema, appendiceal dilation, no serosal exudate
Suppurative Edematous, congested vessels, fibrinopurulent exudate; peritoneal fluid increased, clear or turbid; may be walled off by omentum, adjacent bowel or mesentery
Gangrenous Similar to suppurative plus areas of gangrene, microperforations, increased and purulent peritoneal fluid
Perforated Obvious defect in wall of appendix; thick and purulent peritoneal fluid; may be associated with ileus or bowel obstruction
Abscess Appendix may be sloughed; abscess at site of perforation: right iliac fossa, retrocecal, or pelvic; may present rectally; thick, malodorous pus


A classic presentation of acute appendicitis includes periumbilical pain that migrates to the right lower quadrant, representing a progression from visceral pain to parietal pain that may occur within a few hours or a few days. Physical examination often reveals point tenderness at McBurney’s point, located two-thirds the distance from the umbilicus to the right anterior superior iliac spine. Worsening or diffuse abdominal pain or tenderness are concerning for perforation and peritonitis, as are fevers greater than 38.5°C (101.3°F). Occasionally a palpable mass may be felt in the right lower quadrant, suggestive of a walled-off abscess.

Onset of pain is classically followed by anorexia and nausea, and vomiting may occur. Absence of anorexia and repeated episodes of emesis suggest an alternate diagnosis. Importantly, the classic symptoms of acute appendicitis have limited sensitivity due to variant locations of the appendix and inflammatory irritation of nearby organs. A retrocecal appendicitis may present as flank or back pain, whereas an inflamed appendix in the pelvis may present as dysuria or be confused with testicular or gynecologic diseases. Inflammation of adjacent bowel may cause either an ileus or diarrhea, especially in cases of gross perforation or abscess.

The recent advances in ultrasonography and computed tomography (CT) have markedly improved the accurate diagnosis of appendicitis, especially in “atypical” cases. Ultrasound is noninvasive and an excellent way to evaluate young children for whom avoidance of radiation is desirable. However, the usefulness of ultrasound is technician-dependent and often limited by patient habitus (ultrasound waves penetrate poorly through fat). CT, optimally with IV and PO contrast, yields excellent sensitivity and specificity, but is costly and carries the risk of radiation and contrast exposure. Many diseases may mimic acute appendicitis and it is essential to combine history, physical exam, laboratory values, and imaging studies with clinical experience and judgment to minimize the rate of misdiagnosis.


The mainstay of treatment for simple acute appendicitis is prompt surgical removal of the appendix. To prevent progression leading to perforation, it is important to achieve timely and proper source control. While some evidence supports using antibiotics alone to treat simple acute appendicitis, it is our opinion that appendectomy remains the standard of care. Antibiotics alone carry a significant risk of primary failure leading to perforation as well as disease recurrence, and the now widespread use of laparoscopic appendectomy results in lower rates of surgical complications and shorter hospital stays than were achieved with open appendectomy.

Similarly, surgery remains the standard of care for suppurative, gangrenous, and perforated appendicitis. The exception to urgent surgical intervention for acute appendicitis is perforated appendicitis associated with a contained abscess. In such cases, percutaneous drainage together with antibiotics and interval laparoscopic appendectomy in 6 weeks may be the best treatment strategy, to avoid injury to the small bowel and colon. Antibiotic selection should be tailored to the polymicrobial nature of the disease. Typically, an antipseudomonal β-lactamase is used, such as meropenem, cefepime, or piperacillin/taxobactam. In cases of β-lactamase allergy, combinations such as ciprofloxacin and metronidazole can be used. The most common bacteria that lead to a postoperative infection after appendectomy are: (1) Bacteroides, (2) Klebsiella, (3) Enterobacter, and (4) E. coli, although many of these infections are polymicrobial. Gram-positive cocci are less frequently isolated.

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Jun 18, 2016 | Posted by in INFECTIOUS DISEASE | Comments Off on Acute appendicitis

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