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  • Appendicitis is the most common surgical illness of childhood.

  • The presentation of appendicitis in children is variable, and many other conditions mimic it, such as right lower lobe pneumonia, mesenteric adenitis, and gastroenteritis.

  • Blood tests such as white blood cell count, C-reactive protein (CRP), and procalcitonin can be helpful, but are not reliable for excluding appendicitis.

  • Diagnostic imaging is not required in children with a high clinical probability of appendicitis.

  • Ultrasound is the initial imaging modality of choice, with computed tomography (CT) reserved for nondefinitive sonographic studies.

  • Clinical decision rules that identify low risk for appendicitis should be used to avoid clinical investigations in these children.

Appendicitis is the commonest surgical emergency in children and its prompt identification is often challenging. Meticulous history and physical examination supported by the judicious use of diagnostic imaging are the mainstays of its diagnosis.

Lifetime appendicitis risk is approximately 8%, with males slightly higher than females. Under the age of 3 years, perforation rates are close to 100%, likely secondary to delays in presentation, and missed diagnosis secondary to overlap of symptoms with more common ailments such as gastroenteritis. In adolescence, perforation rates decrease to approximately 15%. Appendicitis is more common in the early summer when enteric infections are high as well.1

The infant’s appendix is somewhat funnel-shaped and becomes tubular after the age of 2 years.1 Appendicitis begins with luminal obstruction by an appendicolith, foreign body, parasite, or lymphoid follicle hyperplasia. This leads to continued inflammation, mucous production, and eventual perforation resulting in peritonitis or abscess formation. Perforation rates range between 25% and 40%.

Missed appendicitis is one of the most frequent reasons for litigation in pediatrics. Appendicitis is missed upon first presentation up to 28% of the time. Gastroenteritis, constipation, and urinary tract infections are common diagnoses in those patients with a misdiagnosis.1


The history is a crucial part of the evaluation of acute appendicitis, and particular features of the history will vary with age. The diagnosis is particularly challenging in children less than 3 years old because preverbal children cannot provide history, and the clinical course is often more rapid and frequently atypical compared with older children. Young children will more often have vomiting and irritability as their primary presentation, which has significant overlap with other diagnoses. Abdominal pain is not easy to elicit from a history, and if so, the patients are less likely to have focal right lower quadrant pain than older children. Because they frequently have perforated appendicitis at diagnosis, they have higher temperatures and higher rates of bilious emesis and bowel obstruction.

As children become more verbal, and the anatomy of the appendix changes, the historical features tend to become more reliable. The classic presentation of periumbilical pain, nausea, and migration of pain to the right lower quadrant is less ...

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