Acute abdominal pain in children: SAQ

This boy has acute appendicitis. The migration of pain from the periumbilical region to the right iliac fossa over a day, the anorexia and vomiting after the pain began, the low-grade fever, and the right iliac fossa tenderness with peritoneal signs of guarding and pain on coughing and hopping, together with the leukocytosis and neutrophilia, make appendicitis the leading diagnosis and demand active confirmation rather than discharge. [1]

Question 1 (10 marks)

Explain the pathophysiology behind the migration of pain, calculate and interpret his Pediatric Appendicitis Score, and describe the imaging you would arrange. (5 marks for the pain pathway; 3 marks for the score; 2 marks for imaging.) [1]

The migration of pain in appendicitis reflects the progression from visceral to somatic pain. Early obstruction and inflammation of the appendix irritate the midgut visceral afferents, which enter the spinal cord at around the tenth thoracic segment, where the abdominal wall around the umbilicus is also represented, so the pain is felt as a vague central periumbilical ache. As the inflamed appendix reaches the parietal peritoneum of the right lower quadrant, somatic pain from the segmentally innervated parietal peritoneum sharpens and localises to the right iliac fossa and is worsened by movement. This migration from central to right lower quadrant pain is the most discriminating historical feature for appendicitis. [1]

His Pediatric Appendicitis Score is ten out of ten. The score combines eight variables into a maximum of ten points: right lower quadrant tenderness scores two, and pain on coughing, hopping or percussion scores two, while migration of pain, anorexia, nausea or vomiting, fever, leukocytosis and neutrophilia each score one. He has right lower quadrant tenderness, pain on coughing and hopping, migration, anorexia, vomiting, fever, leukocytosis and neutrophilia, so he scores the maximum. A high score places him in the high-risk band and prompts urgent surgical referral. [1]

Ultrasound is the first-line imaging modality in suspected appendicitis in children and is preferred because it avoids the ionising radiation of computed tomography. A systematic review has confirmed acceptable diagnostic accuracy for ultrasound even when performed by non-radiologists. Computed tomography is reserved for the case where ultrasound is equivocal and the child remains a diagnostic concern, and magnetic resonance imaging is an alternative in some centres. A pregnancy test is mandatory in any adolescent girl before imaging, though it is not relevant here. [2]

Question 2 (10 marks)

Outline your immediate management, including resuscitation and analgesia, and discuss the risks of delayed diagnosis and the role of antibiotics versus surgery. (5 marks for resuscitation and analgesia; 5 marks for delayed diagnosis and the surgery versus antibiotics decision.) [2]

Immediate management keeps him nil by mouth, secures intravenous access, sends bloods including a group and hold, and gives early titrated analgesia. The child with a suspected surgical abdomen must not be left in pain to preserve the abdominal signs, because a paediatric review found that opioid analgesia relieves pain without reducing the accuracy of examination or the rate of correct diagnosis. A bolus of isotonic crystalloid is given if he is dehydrated or in shock, glucose is checked, and antibiotics covering enteric Gram-negative organisms and anaerobes are given for suspected perforation or peritonitis. A surgeon is called early and the plan proceeds to appendicectomy. [3]

The key risk of delayed diagnosis is perforation. As appendiceal inflammation progresses from mucosal through transmural involvement, ischaemia and gangrene give way to perforation with purulent or faecal peritonitis, which lengthens the admission and raises morbidity through sepsis, ileus and abscess. A study of delayed appendicitis diagnosis found that a substantial proportion of cases were preventable with better recognition of the clinical features, so clinical skill rather than more scanning is the chief safeguard, and the very young child is most at risk because the presentation is atypical. [4]

The 2025 World Society of Emergency Surgery guidelines reaffirm prompt appendicectomy as the reference standard for acute appendicitis, while recognising a role for antibiotics in selected uncomplicated cases. A Cochrane review comparing appendicectomy with antibiotic treatment found that antibiotics can avoid operation in a proportion of children but carry a higher risk of recurrence and later appendicectomy, so surgery remains the definitive option and antibiotics are reserved for selected patients or when an operation is contraindicated. For this high-risk boy with peritoneal signs, the correct plan is resuscitation, antibiotics and prompt appendicectomy. [2]