PC3059: An Equivocal Presentation of Acute Appendicitis with Periappendiceal Abscess in a Three-year-old Patient: A Case Report

Introduction: Although acute appendicitis is a common condition that occurs in thousands of US children each year, diagnosis can be challenging in the pediatric population. This is in part due to variability in presentation, overlap of symptoms with common childhood illnesses, and the limited ability of young children to express themselves. This can lead to delayed diagnosis in children and an increased incidence of complex appendicitis, which includes complications such as perforation, abscess formation, peritonitis, and sepsis.

Case Description: A three-year-old female was brought to the emergency department (ED) after 3 prior visits to the ED for a two-month history of abdominal pain beginning after a diagnosis of Hand, Foot, and Mouth disease (HFMD). During her prior visits, she was diagnosed with constipation and viral gastritis respectively. Upon the third visit, exam findings were reportedly unremarkable. Upon the fourth visit, in contrast to the prior ones, the mother reported that the patient was febrile, anorexic, and now ambulating bent over clutching her abdomen, although these symptoms resolved with administration of acetaminophen and ibuprofen. Initial vital signs and full review of systems were otherwise negative. Her abdomen was non-distended, with normoactive bowel sounds, was non-tender to palpation and without peritoneal signs. Repeat evaluation demonstrated a 102.1°F temperature and the development of guarding. Lab results showed a WBC count of 16.5 with 54% PMNs and platelets 776. Given the history and concerning findings, a CT of the abdomen and pelvis was obtained. CT imaging was remarkable for a retrocecal acute appendicitis with periappendiceal abscess extending from the cecum to the liver. The patient was transferred to a tertiary care center for evaluation by pediatric surgery for complex appendicitis.

Discussion: Classically, acute appendicitis presents with periumbilical pain progressing to right lower quadrant abdominal pain associated with vomiting, fever, and anorexia. Unfortunately, overlap with common childhood ailments makes these findings non-specific for appendicitis and their absence does not rule out the diagnosis. In children, the genesis of appendicitis can occur with appendiceal obstruction caused by lymphoid hyperplasia following a viral infection such as HFMD. Atypical presentation coupled with the inability to express complaints or verify symptoms adds another confounding variable and can ultimately lead to delayed diagnosis and perforation, as in this case.

Conclusion: This case serves as a reminder for physicians to maintain a high suspicion of appendicitis in pediatric patients, especially those below five years old, that present with equivocal findings. In the setting of preceding viral illness or multiple ED visits, a detailed history should be conducted to elucidate the course of symptoms, characteristics of febrile episodes and associated symptoms, and should lead to further investigation by the physician if the pattern, exam, or history is atypical.