Acute Appendicitis
On this page
Direct answer
Acute appendicitis is inflammation of the vermiform appendix, classically beginning as vague periumbilical colicky pain that shifts over 12 to 48 hours to the right iliac fossa, with anorexia, nausea and low-grade fever. The diagnosis is clinical, supported by the Alvarado score, with ultrasound as the first-line imaging investigation in Indian practice and CT reserved for doubtful cases. Uncomplicated appendicitis is treated by appendicectomy, while an appendicular mass presenting after several days is managed conservatively first.
What you must remember
- The classic sequence is periumbilical visceral pain migrating to the right iliac fossa as parietal peritoneum is irritated; anorexia precedes pain, and pain before vomiting favours appendicitis over gastroenteritis.
- McBurney point lies at the junction of the lateral and middle thirds of the spinoumbilical line; Rovsing, psoas (retrocaecal appendix) and obturator (pelvic appendix) signs localise the organ.
- The Alvarado (MANTRELS) score counts migration, anorexia, nausea, right iliac fossa tenderness, rebound tenderness, fever, leukaocytosis and a left shift; 7 or more strongly supports appendicitis.
- Ultrasound is the first imaging choice — a non-compressible, blind-ending tube over 6 mm with a target appearance; CT is the most accurate test when doubt persists, and MRI is used in pregnancy.
- Atypical presentations: a retrocaecal appendix gives flank pain with a positive psoas sign, a pelvic appendix gives diarrhoea and urinary symptoms with tenderness on rectal examination, and the elderly or diabetic patient may progress silently to gangrene.
- An appendicular mass, typically after 4 to 7 days, is managed conservatively by the Ochsner-Sherren regimen — intravenous fluids, antibiotics and close monitoring — because oedematous friable planes make surgery hazardous.
- An appendicular abscess presents with a larger, fluctuant, toxic swelling and is drained, percutaneously where possible, with appendicectomy deferred.
Common confusion
Candidates most often confuse the appendicular mass with the abscess: a mass appearing around day 4 to 5 without peritonism is treated conservatively, whereas an abscess with swinging fever and a fluctuant swelling needs drainage. Children with pelvic appendicitis are often mislabelled as gastroenteritis because of diarrhoea and vomiting; focal tenderness, guarding and anorexia redirect the diagnosis. Analgesia does not mask peritoneal signs and should never be withheld.
Exam-focused takeaway
FMGE appendicitis questions follow a fixed script: a young adult with migratory pain, anorexia and right iliac fossa tenderness goes to ultrasound, or straight to surgery when peritonitis is present; an Alvarado score of 7 or more clinches the decision; a five-day-old mass without peritonism goes to conservative Ochsner-Sherren care; and a toxic abscess goes for drainage. Learn the sign-to-position pairs — psoas for retrocaecal, obturator for pelvic — and remember that interval appendicectomy after 6 to 8 weeks, once routine, is now selective.
Frequently asked questions
Which is the first-line imaging investigation for suspected appendicitis?
Ultrasound of the abdomen, showing a non-compressible blind-ending tubular structure over 6 mm; CT is reserved for doubtful cases and MRI for pregnancy.
What is the McBurney point?
The junction of the lateral and middle thirds of the spinoumbilical line, where maximal tenderness is expected in a normally placed inflamed appendix.
What Alvarado score supports a diagnosis of appendicitis?
A score of 7 or more out of 10, built from migration, anorexia, nausea, tenderness, rebound tenderness, fever, leukaocytosis and a left shift.
How is an appendicular mass managed?
Conservatively by the Ochsner-Sherren regimen — fluids, antibiotics and monitored observation — with surgery reserved for deterioration or non-resolution.
What is interval appendicectomy?
Elective removal of the appendix 6 to 8 weeks after successful conservative management of a mass, now offered selectively rather than routinely.
Which sign suggests a retrocaecal appendix?
A positive psoas sign — pain on resisted hip extension or on passive hyperextension of the right hip.