Pediatric Appendicitis Score (PAS)
Eight-item pediatric appendicitis scoring tool with common interpretation thresholds and citations.
Last reviewed: February 26, 2026
Clinical disclaimer
How it works
The Pediatric Appendicitis Score (PAS) assigns points to eight clinical and laboratory findings: right lower quadrant tenderness, pain with cough/percussion/hopping, anorexia, fever, nausea or vomiting, leukocytosis, neutrophilia, and migration of pain to the right lower quadrant. The points are summed to give a total score from 0 to 10.
- Common risk bands: ≤3 points = low risk; 4–6 = intermediate risk; ≥7 = high risk for appendicitis.
- Our implementation follows the widely used Samuel 2002 weights and bands and shows the current risk category alongside the total.
- Use the score to structure your assessment and discussions, not as a stand‑alone diagnostic test.
Clinical use & interpretation
PAS is most informative when interpreted in the context of the child's overall story and exam. A child with a moderate PAS from vague abdominal pain and non‑specific tenderness is different from one with localized peritonitis and high scores driven by multiple high‑specificity findings.
- Low risk (≤3): may be observed with supportive care, clear return precautions, and short‑interval follow‑up, especially if the child is well appearing.
- Intermediate risk (4–6): often prompts ultrasound as a first‑line imaging modality and early involvement of surgery or pediatrics for serial exams.
- High risk (≥7): with classic findings should lead to prompt surgical consultation; imaging decisions are tailored to local practice and access.
Remember that appendicitis can evolve over time. A low score early in the course may rise with progression; persistent or worsening pain always warrants careful reassessment even if the initial PAS seemed reassuring.
Rapid bedside workflow
- Confirm age-appropriate presentation and complete focused abdominal exam before scoring.
- Calculate PAS using current exam/lab data from the same clinical window.
- Map score to risk band and decide next action (observe, image, consult) based on trajectory.
- Reassess pain localization, vitals, and abdominal findings after interventions or time-based observation.
- Document score components, trend, and explicit return/escalation triggers at handoff or discharge.
Reassessment cadence
- Intermediate-risk pathways: repeat focused abdominal and vital reassessment during observation window.
- After analgesia/fluids or symptom evolution: immediate score-context reassessment before disposition.
- Any worsening tenderness, fever, or systemic concern: urgent reassessment and escalation.
Immediate escalation triggers
- Progressive right lower quadrant tenderness with guarding or peritoneal signs.
- Persistent vomiting, fever, or systemic deterioration despite initial supportive care.
- Discordance between reassuring score and concerning clinical trajectory.
- Limited follow-up reliability in a child with evolving abdominal symptoms.
Shift handoff checklist
- PAS total with component drivers and timestamp.
- Serial exam trend and current risk interpretation.
- Imaging/consult status and pending diagnostics.
- Next reassessment interval plus concrete escalation/return thresholds.
Red flags & differentials
Children with suspected appendicitis deserve a broad differential, particularly when features are atypical or when pain is severe but the PAS is only modestly elevated.
- Consider mesenteric adenitis, constipation, gastroenteritis, testicular torsion, ovarian torsion, Meckel diverticulitis, and urinary tract infection.
- Red flags for perforation or complicated appendicitis include high fever, diffuse peritonitis, marked leukocytosis, and signs of sepsis.
- In adolescent girls, pay attention to gynecologic histories (e.g., LMP, pregnancy risk, adnexal tenderness) and consider pelvic ultrasound as part of work‑up.
Related calculators & guides
Frequently asked questions
The PAS combines eight clinical and laboratory findings—including right lower quadrant tenderness, migration of pain, anorexia, fever, vomiting, leukocytosis, and neutrophilia—into a 0–10 score that estimates the likelihood of appendicitis in school-age children.
Use PAS to structure your history and exam and to categorize risk, not to replace judgment. Low scores can support watchful waiting and outpatient follow-up when the child is well appearing; intermediate scores often prompt ultrasound and surgical input; very high scores should accelerate imaging and consultation, especially when exam findings are convincing.
PAS performs best in school-age children. In preschoolers, symptoms are often less specific and perforation is more common; in adolescents, gynecologic conditions and other differentials are more prominent. Use extra caution and a lower threshold for imaging and consultation at the extremes of age.
A very low score (for example, 0–2) in a well-appearing child with a reassuring exam makes appendicitis less likely but does not absolutely exclude it. Provide clear return precautions, arrange follow-up, and instruct caregivers to return if pain localizes, vomiting persists, or fever and tenderness worsen.
Many pathways reserve CT for equivocal ultrasound or complicated cases, especially to limit radiation exposure. Intermediate PAS values often trigger ultrasound as a first step, while very high scores with classic findings may justify early surgical consultation—even if imaging is pending.
Document serial exam findings, why immediate imaging was deferred, and explicit return precautions for worsening pain, fever, vomiting, or localization. Clear safety-net instructions are essential.