Get a quick FREE consult from our AI doctor at the bottom right corner chat.OR talk to our real doctors — after payment you get redirected to our private Telegram chat.
Blog
← Back to Blog
8/17/2025 • 12–18 min read

Appendicitis: Scores, Imaging & When to Operate

Appendicitis is common and time-sensitive. A structured approach—risk scoring, selective imaging, and clear criteria for antibiotics-first vs laparoscopic appendectomy—reduces misses and avoids unnecessary scans and operations.

Clinical Picture & Differentials

  • Classic: periumbilical pain migrating to RLQ, anorexia, nausea/vomiting, low-grade fever.
  • Exam: McBurney point tenderness, rebound/guarding, Rovsing/psoas/obturator signs.
  • Key mimics: gastroenteritis, mesenteric adenitis, ovarian torsion/cyst, ectopic pregnancy, PID, renal colic, Crohn’s flare, Meckel’s, epiploic appendagitis.

Step 1 — Risk Stratify with Scores

Scores guide imaging and observation; they don’t replace judgment.

  • Alvarado (MANTRELS) (0–10): migration, anorexia, N/V, tenderness RLQ (2), rebound, fever, leukocytosis (2), neutrophilia.
  • AIR score (Appendicitis Inflammatory Response): pain, rebound/guarding, temp, WBC, proportion neutrophils, CRP.
  • Pediatrics (PAS): pediatric variant emphasizing RLQ tenderness, migration, anorexia, fever, N/V, leukocytosis/neutrophilia.

Low risk → consider observation ± US; Intermediate → image; High risk → surgical consult and expedited imaging or OR depending on stability/resources.

Step 2 — Imaging Strategy

  • Ultrasound first in children and young/non-obese adults; look for noncompressible blind-ended tubular structure >6 mm, wall hyperemia, appendicolith, periappendiceal fat stranding/free fluid.
  • CT (low-dose, contrast protocol) for equivocal US or adults with higher BMI/atypical features. High sensitivity/specificity; mind radiation stewardship.
  • MRI in pregnancy or when avoiding radiation/iodine; high accuracy without contrast in many centers.
  • If perforation/abscess suspected: CT defines collections and guides IR drainage planning.

Step 3 — Initial ED Management

  • NPO, IV access, analgesia (opioid-sparing multimodal OK), antiemetics.
  • IV fluids to correct dehydration (balanced crystalloids).
  • Pre-op antibiotics once appendicitis is likely: e.g., ceftriaxone + metronidazole or piperacillin–tazobactam for severe/complicated cases; tailor to allergy/local patterns.

Step 4 — Operate or Antibiotics-First?

Uncomplicated Appendicitis (no perforation/abscess/phlegmon)

  • Laparoscopic appendectomy is standard with low complications and short LOS.
  • Antibiotics-first may be offered to select adults who prefer to avoid surgery; requires shared decision-making:
    • Best candidates: imaging-confirmed uncomplicated appendicitis, no appendicolith, stable, reliable follow-up.
    • Expect recurrence risk over months–years; some will later need appendectomy.

Complicated Appendicitis

  • Perforation with abscess/phlegmon: options include nonoperative management (IV antibiotics ± percutaneous drainage) with interval appendectomy in selected cases vs early surgery depending on expertise and clinical course.
  • Generalized peritonitis or sepsis → urgent surgery + broad-spectrum antibiotics and source control.

Antibiotic Regimens (examples; follow local protocols)

  • Uncomplicated peri-op prophylaxis: single pre-incision dose (e.g., cefazolin + metronidazole) often sufficient; some centers give ≤24 h post-op.
  • Complicated: piperacillin–tazobactam, or ceftriaxone + metronidazole; tailor to cultures; typical duration 3–5 days after source control and clinical improvement.
  • Oral step-down when tolerating PO (e.g., amoxicillin–clavulanate) per stewardship.

Post-Op & Disposition

  • Early ambulation, advance diet as tolerated, routine VTE prophylaxis if indicated.
  • Discharge criteria: pain controlled with oral meds, afebrile, tolerating PO, reliable follow-up, wound care instructions.
  • Return precautions: worsening pain, fever, vomiting, wound erythema/drainage.

Special Populations

  • Pregnancy: MRI/US for diagnosis; early surgical consultation; laparoscopy is generally safe in experienced hands with pregnancy precautions.
  • Elderly/diabetics/immunosuppressed: higher perforation risk and atypical presentation—lower threshold for imaging and admission.
  • Pediatrics: US-first, pediatric surgery involvement; perforation rates rise with delay—prioritize throughput.

Quality & Pitfalls

  • Don’t delay analgesia—pain control doesn’t hide the diagnosis.
  • Beware normal WBC early; CRP trends help but are nonspecific.
  • Document shared decision-making if choosing antibiotics-first; ensure rapid return plan for recurrence.

Patient FAQs

“Can antibiotics cure appendicitis?” Sometimes for uncomplicated cases, but there’s a meaningful chance it returns later. Surgery is definitive.

“Is a CT scan always needed?” No. Children and many adults can be diagnosed with ultrasound first; CT or MRI clarifies when US is equivocal or complications are suspected.

References & Notes

Pragmatic pathway: risk scores (Alvarado/AIR/PAS), ultrasound-first in kids/young adults, low-dose CT or MRI as needed, peri-op antibiotics, and thoughtful selection for antibiotics-first vs laparoscopic appendectomy. Local surgical and radiology protocols apply. Educational only.

Educational only, not personal medical advice.