Appendicitis in children is treatable and, diagnosed before perforation, carries an excellent prognosis. The challenge is diagnosis. The classic textbook presentation – central pain moving to the right lower abdomen, fever, and tenderness at McBurney's point – is reliable in older children and adolescents but unreliable in young children, in whom the appendix sits higher, the pain history is harder to obtain, and the inflammatory response is less localised.
The consequence of missing the diagnosis is perforation. A perforated appendix in a child leads to peritonitis, abscess, and a significantly more complicated recovery. Parents who know what to watch for and when to seek urgent assessment make the difference.
Healthbooq (healthbooq.com) covers childhood surgical conditions and emergencies.
What the Appendix Is and Why It Causes Problems
The appendix is a finger-like pouch attached to the caecum at the junction of the small and large intestine. It has no established essential function in humans. Appendicitis occurs when the appendix becomes obstructed – commonly by a faecolith (a hard piece of stool), by swollen lymph nodes associated with a gut infection, or by other material – leading to bacterial overgrowth, inflammation, and if untreated, perforation.
The peak age of appendicitis is 10-14 years. It is less common in children under 5 but more dangerous in this group because the omentum (the fatty tissue that can wall off infection) is less developed, the child's ability to describe symptoms is more limited, and the threshold for investigation may be lower in a system more familiar with viral illness than surgical emergency in toddlers.
The Classic Presentation
In older children and adolescents, appendicitis typically begins with central or umbilical abdominal pain – the visceral pain from the inflamed appendix, poorly localised by the gut's nerve supply. Over 12-24 hours, the pain migrates to the right lower quadrant as the inflammation extends to the peritoneum, which is well supplied with somatic pain fibres and produces precisely localised, sharp pain.
Associated features include: low-grade fever (typically 37.5-38.5 degrees in early appendicitis, higher with perforation); nausea and vomiting, usually after the pain starts (vomiting before significant pain suggests gastroenteritis rather than appendicitis); loss of appetite; and reluctance to move because movement worsens peritoneal pain.
McBurney's point is the classic location of maximal tenderness, one-third of the way along an imaginary line from the right anterior superior iliac spine (the bony prominence of the hip) to the navel. Rebound tenderness (pain that is worse when pressure is released than when it is applied) and Rovsing's sign (pain felt in the right lower quadrant when the left lower quadrant is pressed) indicate peritoneal irritation.
Atypical Presentations
Children under 5 frequently do not follow the classic pattern. Pain may be diffuse and poorly described. Fever may be higher. The child may simply be irritable, refusing food, and reluctant to walk. Given the overlap with many common childhood illnesses, a high index of suspicion is essential.
A child who has had central abdominal pain for 24 hours and is now refusing to walk, lying still with their legs drawn up, and not interested in food should be assessed urgently regardless of whether localised right lower quadrant pain is clearly identifiable.
Girls approaching puberty add a further diagnostic challenge because ovarian pathology (ovarian cysts, torsion, Mittelschmerz) can produce right-sided pain that overlaps considerably with appendicitis.
Investigations
White cell count and CRP are almost always raised in appendicitis but are non-specific. The C-reactive protein level correlates roughly with disease severity: very elevated CRP (above 100 mg/L) increases the likelihood of perforation. Urinalysis is useful to exclude urinary tract infection, which can cause right-sided abdominal pain and can also cause mild white cell elevation.
The Paediatric Appendicitis Score (PAS), developed by Madan Samuel (2002, Journal of Pediatric Surgery), scores clinical and laboratory findings to stratify low, intermediate, and high probability of appendicitis. An Alvarado score is widely used in adults and older teenagers.
Ultrasound is the first-line imaging modality in children, avoiding radiation. It is operator-dependent and may be inconclusive if the appendix is not visualised. If ultrasound is inconclusive and clinical concern remains high, MRI is preferred over CT in children to avoid ionising radiation, though CT provides faster, more reliable imaging and is used when MRI is unavailable or when the child is unstable.
Treatment
Appendectomy – surgical removal of the appendix – is the definitive treatment. Laparoscopic (keyhole) appendectomy is now the standard approach in most UK paediatric surgical centres. It involves a shorter recovery than open surgery and lower rates of wound infection.
Non-operative management (antibiotics alone, without surgery) is an area of active research and is used in selected adults and some children with uncomplicated appendicitis at specialist centres. The APPY-1 and COMPASS trials have explored this approach. It avoids surgery but carries a 20-30% rate of recurrence requiring eventual appendectomy within 5 years, and it is not currently standard practice in UK paediatric surgery.
A perforated appendix is managed with appendectomy plus IV antibiotics, and in the case of abscess, sometimes with initial drainage followed by interval appendectomy.
Key Takeaways
Appendicitis is the most common surgical emergency in childhood, with a peak incidence between 10 and 14 years of age. The classic progression is central abdominal pain migrating to the right lower quadrant, accompanied by fever, nausea, and loss of appetite. In young children under 5, presentation is often atypical and diagnosis is frequently delayed, leading to higher perforation rates in this age group. Perforation rates in children are approximately 30-40% at presentation, compared with 20% in adults, partly because of diagnostic delay. The Paediatric Appendicitis Score (PAS) and Alvarado score are validated clinical scoring tools. Imaging with ultrasound (first-line) and CT or MRI (if ultrasound inconclusive) supports diagnosis. Treatment is appendectomy, increasingly performed laparoscopically; non-operative management with antibiotics is used in selected uncomplicated cases in some centres.
