Acute Appendicitis

Separate uncomplicated from complicated disease

The treatment conversation changes when gangrene, perforation, abscess, phlegmon, or diffuse peritonitis is present.

Uncomplicated appendicitis has an inflamed appendix without perforation, abscess, phlegmon, or generalized peritonitis.

Complicated disease requires source-control thinking and antibiotics; a contained abscess differs from free perforation with diffuse contamination.

Use examination signs as anatomy probes

No single maneuver is sensitive enough to exclude appendicitis, but each can localize irritated tissue.

McBurney point tenderness and rebound reflect local parietal irritation near the usual appendix base.

A psoas sign supports irritation from a retrocecal appendix, while an obturator sign supports a pelvic appendix contacting the obturator internus.

Rovsing sign reproduces right lower quadrant pain with left-sided palpation and supports peritoneal irritation.

Use scores to set probability, not replace judgment

Clinical scores can identify low-risk patients and guide imaging, but pregnancy, age extremes, and atypical anatomy reduce reliability.

The Alvarado score combines migration, anorexia, nausea or vomiting, tenderness, rebound, fever, leukocytosis, and neutrophil shift.

A low score can support discharge or observation with safety-netting in an appropriate patient; intermediate risk usually benefits from imaging.

Perforation risk rises with delay, but a rigid hour cutoff is less useful than disease severity, access, and timely source control.

Choose imaging for the patient in front of you

Imaging balances diagnostic performance, radiation, pregnancy, body habitus, and local expertise.

Graded-compression ultrasound is a useful first study in children and pregnancy when expert performance is available; a nondiagnostic study does not exclude appendicitis.

Contrast-enhanced CT is highly accurate in nonpregnant adults and identifies alternate diagnoses and complications.

MRI avoids ionizing radiation and is preferred in pregnancy after nondiagnostic ultrasound when available; some centers use MRI first.

Follow obstruction to perforation

Delay allows a closed-loop luminal process to become ischemic and contaminated.

A fecalith, lymphoid hyperplasia, or less common luminal lesion obstructs outflow while mucus secretion continues.

Rising intraluminal pressure impairs lymphatic and venous drainage, promotes bacterial overgrowth, and compromises perfusion.

Ischemic wall injury progresses to necrosis, gangrene, and perforation, which may be walled off or spill freely into the peritoneum.

The same sequence explains both pain migration and the cost of delay.

Choose surgery or selected nonoperative care

Appendectomy remains standard definitive therapy, while antibiotics alone are a preference-sensitive option for carefully selected uncomplicated disease.

Laparoscopic appendectomy provides definitive source control and avoids recurrence from a retained appendix.

Antibiotic-first treatment can succeed in selected stable adults with imaging-confirmed uncomplicated appendicitis, but recurrence and later appendectomy remain possible and an appendicolith predicts more failure.

Stable localized abscess may receive antibiotics with percutaneous drainage when accessible; generalized peritonitis or uncontrolled sepsis requires urgent operation.