Appendicitis is inflammation of the vermiform appendix, usually due to luminal obstruction.
It is the most common surgical emergency in the UK.
🚨 Delay in diagnosis or treatment increases the risk of perforation, abscess formation, and sepsis.
Common causes of obstruction:
Lymphoid hyperplasia (children, young adults)
Faecoliths (hardened stool)
Less commonly: infections, neoplasms, foreign bodies
Sequence of disease:
Obstruction → mucus build-up, bacterial overgrowth
Rising pressure → ischaemia and inflammation
Risk of perforation → peritonitis or abscess
Typical presentation:
Periumbilical pain migrating to the right iliac fossa
Anorexia, nausea ± vomiting
Low-grade fever, tachycardia
Constipation or diarrhoea possible
On examination:
RIF tenderness at McBurney’s point
Guarding or rebound tenderness
Rovsing’s sign (RIF pain on LIF palpation)
Psoas or obturator signs (retrocaecal or pelvic appendix)
🚨 Sudden pain relief may suggest perforation — reassess urgently.
Gastrointestinal: mesenteric adenitis, Meckel’s diverticulitis, Crohn’s, gastroenteritis
Gynaecological: ectopic pregnancy, ovarian torsion, PID
Urological: UTI, renal colic, testicular torsion
Others: pneumonia (RLL), diabetic ketoacidosis
💡 Always exclude pregnancy in women of reproductive age.
Bedside: obs, urine dip, pregnancy test
Bloods: raised neutrophils, elevated CRP, check renal function
Imaging:
Ultrasound: first-line in children, young women, pregnancy
CT: gold standard in adults
MRI: useful in pregnancy
Scoring system (Alvarado): combines symptoms, signs, and bloods.
≥7 = likely appendicitis (surgical referral)
5–6 = possible (consider imaging)
<5 = unlikely
Initial: IV fluids, analgesia, antibiotics, nil by mouth
Definitive: surgical appendicectomy (laparoscopic usually preferred)
Open surgery may be chosen in specific scenarios (e.g. haemodynamic instability, limited resources, uncorrected coagulopathy).
💡 Some uncomplicated cases may be treated with antibiotics alone, but this is not routine in the UK.
Perforation and generalised peritonitis
Appendiceal abscess or pelvic collection
Sepsis
Wound infection or ileus post-op
Rare: infertility following pelvic sepsis
Early surgery → excellent outcomes
Perforation increases morbidity and length of stay
Recurrence is rare after appendicectomy
Fries Tips
Migratory abdominal pain is a classic feature.
Anorexia is very common — always ask.
Alvarado ≥7 = likely appendicitis.
Always check urine dip and pregnancy test before referral.
In children/pregnancy → use ultrasound, not CT.
