Acute appendicitis is the most common abdominal surgical emergency worldwide, defined as acute inflammation of the vermiform appendix is a small, blind-ended tubular structure arising from the caecum at the confluence of the taenia coli in the right iliac fossa. It affects all age groups but peaks in the second and third decades of life. The underlying pathology begins with luminal obstruction most commonly by a faecolith, lymphoid hyperplasia or inspissated mucus leading to bacterial overgrowth, rising intraluminal pressure, mucosal ischaemia and progressive transmural inflammation. Without timely intervention, the appendix proceeds to gangrene and ultimately perforation, releasing infected contents into the peritoneal cavity and causing localised abscess formation or generalised faecal peritonitis a life-threatening complication that dramatically increases morbidity and mortality.
Symptoms
The classical presentation begins with central, periumbilical colicky pain that migrates within 12–24 hours to the right iliac fossa as the overlying parietal peritoneum becomes inflamed a progression known as McBurney's point tenderness, which remains the hallmark clinical sign. Anorexia is an almost universal accompanying feature and its absence should cast doubt on the diagnosis. Nausea, vomiting and low-grade fever develop as inflammation progresses. On examination, Rovsing's sign and rebound tenderness further support the diagnosis. In perforation, pain becomes generalised, guarding becomes rigid and the patient appears systemically unwell with high fever and tachycardia. Atypical presentations are common when the appendix occupies an unusual position a retrocaecal appendix may present with flank or back pain, while a pelvic appendix can mimic urinary or gynaecological pathology.
Diagnosis
The diagnosis is predominantly clinical, supported by investigations. Blood tests reveal a raised white cell count and elevated CRP, with markedly elevated inflammatory markers suggesting perforation or abscess. Urine dipstick is performed to exclude urinary tract infection and renal colic. Ultrasound is the first-line imaging investigation, particularly in women of childbearing age to exclude ovarian pathology, though its sensitivity is limited by operator experience and body habitus. CT scan of the abdomen and pelvis is the most sensitive and specific investigation, demonstrating a distended, non-compressible appendix greater than (6 mm) in diameter with periappendiceal fat stranding, and identifying perforation, abscess or alternative diagnoses. The Alvarado scoring system combines clinical and laboratory parameters to risk-stratify patients and guide management decisions.
Treatment
Laparoscopic Appendicectomy is the definitive and gold standard treatment surgical removal of the inflamed appendix through three small port incisions under general anaesthesia. The laparoscopic approach offers superior visualisation of the entire abdominal cavity, lower wound infection rates, faster recovery and earlier return to normal activity compared to open surgery and is the preferred approach in both uncomplicated and perforated appendicitis. Intravenous antibiotics are administered pre-operatively and continued post-operatively in cases of perforation or gangrenous appendicitis. For appendiceal abscess where perforation has resulted in a contained collection initial management with IV antibiotics and CT-guided percutaneous drainage may be employed, with interval appendicectomy performed 6–8 weeks later once inflammation has fully resolved. Non-operative management with antibiotics alone has gained interest for uncomplicated appendicitis in selected cases, though recurrence rates of 20–35% within 5 years mean that surgical treatment remains the standard of care for the majority of patients.