EM@3AM – Appendicitis

Author: Erica Simon, DO, MHA (@E_M_Simon, EM Chief Resident, SAUSHEC, USAF) // Edited by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UT Southwestern Medical Center / Parkland Memorial Hospital) and Brit Long, MD (@long_brit, EM Attending Physician, SAUSHEC, USAF)

Welcome to EM@3AM, an emdocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

An 8-year-old female presents to the emergency department for abdominal pain. Per the patient, the pain began the day prior in the “middle of her stomach,” but is now “lower to the right” and associated with chills. The patient has yet to reach menarche; she is not sexually active. Review of systems is negative for diarrhea, sick contacts, and recent travel.

Triage VS: BP 117/72, HR 128, T 102.4 Oral, RR 18, SpO2 99% on room air.

Physical exam is significant for tenderness to palpation at McBurney’s point, a positive psoas sign, and a positive Rovsig’s sign.

What’s the next step in your evaluation and treatment?

Answer: Appendicitis1-4

  • Presentation: Classically: vague periumbilical abdominal pain which migrates to the RLQ (inflamed appendix resulting in localized peritoneal irritation), with associated nausea, emesis, anorexia, +/- diarrhea.
    • Atypical presentations: retroperitoneal appendix: flank or back pain; appendiceal tip residing in the pelvis: suprapubic pain.
  • Physical Exam:
    • VS: fever, tachycardia
    • Abdominal exam:
      • McBurney’s point tenderness – anatomically a point 1/3 the distance between the anterior superior iliac spine and umbilicus
      • Rovsing’s sign – RLQ pain on palpation of the LLQ
      • Obturator sign –  lower quadrant pain upon internal rotation of the hip (pelvic appendix)
      • Psoas sign – pain with extension of the ipsilateral hip (retroperitoneal appendix)
      • Diffuse peritonitis: suggests appendiceal perforation
  • Evaluation:
    • Labs:
      • CBC: leukocytosis is common, however a normal WBC count does not exclude the diagnosis (10% of patients with a normal WBC have an appendicitis).2
      • UA: leukocyte esterase and sterile pyuria not are unusual, i.e. – a positive UA does not refute the diagnosis.1
    • Imaging:
      • The Infectious Diseases Society of America and the Surgical Infection Society recommend CT with IV contrast (sensitivity 90-100%, specificity 91-99%3). Oral and rectal contrast are not advised.
        • CT findings: thickened appendix (>7mm diameter) with mural enhancement and surrounding stranding indicative of inflammation. Periappendiceal fluid or air => perforation.1
  •  Treatment:
    • Parenteral antibiotics directed against gram negative and anaerobic organisms.
    • Fluid resuscitation, antipyretics, antiemetics as appropriate.
    • Surgical consult: laparoscopic vs. open appendectomy.
  • Pearls:
    • Consult early.
    • Take time to consider the differential diagnoses of appendicitis:1
      • Gastroenteritis, mesenteric adenitis, inflammatory bowel disease, nephrolithiasis, urinary tract infection, Meckel’s diverticulitis, intussusception, testicular torsion, ectopic pregnancy, ovarian torsion, ruptured ovarian cyst, PID, endometriosis, and malignancy.
        • Neutropenic patient: consider typhlitis
      • Appendicitis is the most common non-obstetric emergency in pregnancy (risk of pre-term labor 11%; fetal loss 6% with complicated cases):1
        • May present with RUQ pain secondary to displacement of the appendix by the gravid uterus.
        • Evaluation: Ultrasound with graded compression (78% sensitivity, 83% specificity4), followed by MRI without gadolinium contrast if ultrasound inconclusive.
          • If MRI not readily available: may consider CT (8% negative appendectomy rate as compared to 54% by clinical assessment alone, vs. 32% by clinical assessment + ultrasound4) => experts argue that CT radiation is below the threshold to induce fetal malformations, and that the majority of appendicitis cases occurring during the second and third trimesters when organogenesis is complete.


  1. Richmond B. The Appendix. In Sabiston Textbook of Surgery. Philadelphia, Elsevier Saunders. 2017; 1296-1311.
  2. Andersson R. Meta-analysis of the clinical and laboratory diagnosis of appendicitis. Br J Surg. 2004; 91:28-37.
  3. Birnbaum B, Wilson S. Appendicitis at the millennium. Radiology. 2000; 215: 337-348.
  4. Khandelwal A, Fasih N, Kielar A. Imaging of acute abdomen in pregnancy. Radiol Clin North Am. 2013; 51:1005-1022.

For Additional Reading:

Appendicitis: Pearls and Pitfalls in Adult and Pediatric Populations



Ultrasound for Appendicitis:

Ultrasound for Appendicitis

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