- Perforation: sudden worsening of pain, peritonitis, high fever – immediate surgery
- Appendiceal abscess: palpable mass, prolonged symptoms – may require percutaneous drainage before surgery
- Sepsis: hypotension, tachycardia, altered mental status
Acute Appendicitis
Must-Not-Miss / Red Flags
Patient Explanation
“Your appendix, a small pouch attached to your intestine, has become infected and inflamed. We’ll remove it with a small operation before it bursts.”
Board Fact
“The Alvarado score helps predict appendicitis: RLQ tenderness + leukocytosis + migration of pain = high probability.”
ICD-10
K35.80
Definition & Core Concept
Acute appendicitis is an acute inflammation of the vermiform appendix, most commonly caused by luminal obstruction by a fecalith, lymphoid hyperplasia, or neoplasm, leading to bacterial overgrowth and ischemia.
Epidemiology & Risk Factors
- Lifetime risk: 7‑8%
- Most common in ages 10‑30 years
- Male‑to‑female ratio 1.4:1
Clinical Vignette
A 20‑year‑old man presents with 12 hours of periumbilical pain that has now localized to the right lower quadrant. He has anorexia and one episode of vomiting. Abdominal CT shows a dilated 10 mm appendix with periappendiceal fat stranding and a small appendicolith. No perforation is seen.
Pearls & Pitfalls
- Not all appendicitis requires immediate surgery – uncomplicated appendicitis can be treated with antibiotics alone, though appendectomy is definitive and preferred in most settings.
- In elderly patients, consider appendiceal malignancy (particularly adenocarcinoma or carcinoid) if presentation is atypical or mass is present.
Discharge & Follow-Up
Post‑op: advance diet as tolerated, activity restrictions for 2 weeks, wound check at 10‑14 days. If antibiotics only: close follow‑up for recurrence.
Literature & Guidelines
WSES Jerusalem 2024 Guidelines on Acute Appendicitis. PMID: 38672310.