Pediatric Appendicitis Score Calculator

Eight items, 0 to 10, derived in 1,170 children aged 4 to 15. Its derivation paper reported 100% sensitivity at a cut-off of 6; the best independent validation found 92.8% sensitivity and 69.3% specificity at that same 6, and proposed two thresholds instead of one.

Last updated 8 Oct 2026

Pediatric Appendicitis Score

8 items, 0 to 10

Tenderness in the right lower quadrant on cough, percussion or hoppingThe heaviest item alongside right iliac fossa tenderness, worth 2 points, and the one that does most of the work: asking a child to hop, or percussing gently, elicits peritoneal irritation without the guarding a frightened child produces on deep palpation. A best-evidence review of hopping as a sign exists precisely because this item is doing the heavy lifting.

Tenderness in the right iliac fossaThe other 2-point item. Both heavy items are elicited at the same part of the examination, which is worth noticing: a single unconvincing examination moves 4 of the 10 available points at once, and the score has no way to express uncertainty about them.

Migration of pain to the right lower quadrantMigration, not location. Pain that began periumbilically and moved is the classic history; pain that has been right-sided throughout scores nothing here even if the right iliac fossa is tender.

AnorexiaA history item and a genuinely useful one in children, where it is often the parent rather than the child who reports it reliably.

Nausea or vomitingOne point whether nausea alone or vomiting; the item is not graded. Vomiting before the onset of pain points away from appendicitis clinically and the score cannot express that — it scores the symptom, not its sequence.

Fever of 38.0 °C or aboveThe published threshold is 38.0 °C (100.4 °F). Early appendicitis is commonly afebrile, so this item scoring 0 says little; a high fever in a child with abdominal pain has a long differential that this score does not address.

Leucocytosis — white cell count 10,000/mm³ or aboveTake the figure from the reader’s own full blood count report. The absolute neutrophil count calculator converts a differential into the count the next item needs. Note a published inconsistency worth knowing: the derivation paper’s text uses “over 10,000” while its own table uses “10,000 or more”, so a count of exactly 10,000 scores differently depending on which rendering is read. This page implements 10,000 or more.

Neutrophilia — absolute neutrophil count over 7,500/mm³Strictly the polymorphonuclear neutrophil count, over 7,500/mm³. It is the only item on the score that cannot be obtained at the bedside, and it is the reason a score taken before the blood result is a different number from the same score taken after it. Score what you have and say which.

9pointsExample

Tenderness on cough (2); right iliac fossa tenderness (2); pain migrated (1); anorexia (1); nausea (1); no fever (0); white cells 12,400 (1); neutrophils 9,100 (1)

Scoring, and the cut-off nobody agrees on

PAS = RLQ tenderness on cough, percussion or hopping (2) + right iliac fossa tenderness (2) + migration of pain (1) + anorexia (1) + nausea or vomiting (1) + fever 38.0 °C or above (1) + leucocytosis 10,000/mm³ or above (1) + neutrophilia over 7,500/mm³ (1)
Minimum 0 · maximum 10

the derivation: 1,170 children aged 4 to 15 with abdominal pain, in the paper that introduced the score in 2002. It split the score at 6 and reported sensitivity 100% (95% CI 99.2 to 100) and specificity 92% (89.0 to 94.2) — figures quoted here as reported by the independent validation below, since the 2002 paper is not open access
the independent validations disagree with it: a 2008 Toronto cohort of 849 children aged 1 to 17 reported sensitivity 97.6% and specificity 96.0% using cut-points of 2 and 7; the 2009 Montreal cohort of 246 children aged 4 to 18, with 34% appendicitis, found sensitivity 92.8% and specificity 69.3% at the derivation paper’s own cut-off of 6, and the authors of that study considered the 2008 methodology flawed. Three studies, three answers
two thresholds, not one: the Montreal authors proposed 4 or less as a low stratum (sensitivity 97.6%, negative predictive value 97.7%) and 8 or more as a high one (specificity 95.1%, positive predictive value 85.2%), leaving 5 to 7 explicitly indeterminate. That is what this page implements, because a single cut-off forces the indeterminate middle into one side or the other
two items are not bedside items: leucocytosis and neutrophilia need a blood count. A score computed before the result is back has a maximum of 8 and is not the instrument that was validated
and the comparison with the Alvarado score: a prospective paediatric head-to-head found the two scores’ test characteristics similar and neither accurate enough to settle the question without surgical assessment or definitive imaging. The Alvarado item table is not reproduced on this page, which implements the paediatric score

Worked example

Tenderness on cough (2); right iliac fossa tenderness (2); pain migrated (1); anorexia (1); nausea (1); no fever (0); white cells 12,400 (1); neutrophils 9,100 (1)
2 + 2 + 1 + 1 + 1 + 0 + 1 + 1 = 9 points, in the 8–10 stratum
In the 246-child validation cohort, where 34% had appendicitis, a score of 8 or more had a specificity of 95.1% and a positive predictive value of 85.2%
Remove the two laboratory items — the count is not back yet — and the same child scores 7, in the indeterminate band. Nothing about the child changed
Score this child at the derivation paper's single cut-off of 6 instead and they are “compatible with appendicitis” at a reported sensitivity of 100% and specificity of 92%. Score them at the same 6 using the independent validation's figures and the specificity is 69.3%. Both are published, both are on this page, and the difference is 23 percentage points
A score of 0 is the floor and 10 the ceiling; the two 2-point items alone can reach 4. A score is not a diagnosis, and a published figure describes the cohort it came from rather than the child in front of you.

The eight items

Read against two independent reproductions that agree item for item and point for point. Note the right-hand column: six of the eight items are available at the bedside and two are not, so the score has a maximum of 8 until the blood count returns — which is a different instrument from the one that was validated, scored on the same page.
Item	Points	Where it comes from
Tenderness in the RLQ on cough, percussion or hopping	2	Examination — the heaviest item
Tenderness in the right iliac fossa	2	Examination
Migration of pain to the RLQ	1	History
Anorexia	1	History
Nausea or vomiting	1	History
Fever 38.0 °C or above	1	Observation
Leucocytosis, white cells 10,000/mm³ or above	1	Laboratory
Neutrophilia, absolute neutrophils over 7,500/mm³	1	Laboratory

What three studies found at the same cut-offs

The disagreement at a cut-off of 6 is 23 percentage points of specificity, which is why this page implements the two-threshold scheme and prints all three studies rather than picking one. The Montreal authors regarded the 2008 methodology as flawed and said so; printing both is more useful than choosing between them. Predictive values belong to the 34% prevalence of that cohort and not to any other population.
Study	Cohort	Cut-off	Sensitivity	Specificity
Derivation, 2002	1,170 children aged 4 to 15	6 or more	100% (99.2–100)	92% (89.0–94.2)
Toronto validation, 2008	849 children aged 1 to 17	2 and 7	97.6%	96.0%
Montreal validation, 2009	246 children aged 4 to 18, 34% appendicitis	6 or more	92.8%	69.3%
Montreal validation, 2009	the same cohort	4 or less (rule-out)	97.6% (NPV 97.7%)	—
Montreal validation, 2009	the same cohort	8 or more (rule-in)	—	95.1% (PPV 85.2%)

Eight items, three published answers, and two of them need a blood count

The Pediatric Appendicitis Score takes three pieces of history — migration of pain, anorexia, nausea or vomiting — two examination findings worth two points each, a temperature, and two laboratory items, and adds them to between 0 and 10. The two heavy items are where the information is: tenderness in the right iliac fossa, and tenderness in the right lower quadrant provoked by cough, percussion or hopping. Asking a child to hop is in the score because it elicits peritoneal irritation without the guarding that deep palpation produces in a frightened child, and it carries enough weight that a published best-evidence review exists on that sign alone.

What a reader actually needs from this page is the honest state of its validation, because the published figures do not agree and the gap is large. The 2002 derivation study, in 1,170 children aged 4 to 15, split the score at 6 — 5 or less incompatible with appendicitis, 6 or more compatible — and reported a sensitivity of 100% with a specificity of 92%. A 2008 Toronto validation in 849 children aged 1 to 17 reported 97.6% and 96.0% using cut-points of 2 and 7. A 2009 Montreal validation in 246 children aged 4 to 18, with a 34% prevalence of pathology-confirmed appendicitis, found that at the derivation paper’s own cut-off of 6 the sensitivity was 92.8% and the specificity 69.3%. That is twenty-three percentage points of specificity between two studies using the same number, and the Montreal authors separately regarded the 2008 methodology as flawed. All three sets of figures are printed on this page rather than reduced to one.

Their response to that spread is what this page implements: two thresholds rather than one, with a deliberately indeterminate middle. Four or less had a sensitivity of 97.6% and a negative predictive value of 97.7%; eight or more had a specificity of 95.1% and a positive predictive value of 85.2%; five to seven was left unresolved, which is a more honest description of a child in the middle of this score than forcing them to one side of a single cut-off. Both predictive values belong to that cohort’s 34% prevalence and to no other. A paediatric head-to-head against the Alvarado score found the two similar and neither accurate enough to settle the question without surgical assessment or definitive imaging.

One structural point to carry away: two of the eight items are laboratory items, so a score taken before the blood count is back has a maximum of 8 and is not the instrument that was validated. Record which version the number is. A score is not a diagnosis, and a published figure describes the cohort it came from rather than the child in front of you. A single value is a snapshot of one examination: a child whose illness is evolving can score differently an hour later, so a reassuring score does not exclude deterioration, and the trend across serial assessments by the same examiner carries more than any one reading. The derivation population is children aged roughly 4 to 15 presenting with abdominal pain; the score was not derived in adults, in infants, or in children already imaged. Published item wordings and severity bands differ between sources and between units, so the reader’s own unit’s chart and protocol take precedence over any banding printed here. The two laboratory thresholds in this score are method- and laboratory-dependent, so the reader’s own laboratory’s interval and their own unit’s protocol take precedence.

Frequently asked questions

What Pediatric Appendicitis Score means appendicitis is likely?

On the two-threshold scheme this page implements, 8 or more was the high stratum, with a specificity of 95.1% and a positive predictive value of 85.2% in a cohort where 34% of children had appendicitis. The derivation paper used a single cut-off of 6 instead. Neither number is a diagnosis, and the predictive value depends on the prevalence where it is applied.

Can the Pediatric Appendicitis Score rule appendicitis out?

A score of 4 or less had a sensitivity of 97.6% and a negative predictive value of 97.7% in the 246-child Montreal validation, where the prevalence was 34%. That is a rule-out figure in that population; in a population with a different prevalence the same sensitivity gives a different negative predictive value.

Why do published sensitivities for this score differ so much?

Because the cohorts and the methods differ. At a cut-off of 6 the derivation study reported 100% sensitivity and 92% specificity, while an independent validation found 92.8% and 69.3% — twenty-three points of specificity apart. A third study reported 97.6% and 96.0% at different cut-points and its methodology was criticised by the second. This page prints all three.

Can I use the score before the blood results are back?

You can add up the six bedside items, but the maximum is then 8 rather than 10 and the published thresholds were not derived on that version. The same child can move from the high stratum to the indeterminate one purely by losing two laboratory points, so record which version the number is.

Pediatric Appendicitis Score or Alvarado score?

A prospective paediatric head-to-head found their test characteristics similar and concluded that neither was accurate enough to settle the question without surgical assessment or definitive imaging. This page implements the paediatric score and does not reproduce the Alvarado item table.

Related calculators

References

Samuel M. Pediatric Appendicitis Score. J Pediatr Surg. 2002;37(6):877–881 — 1,170 children aged 4 to 15. Its reported sensitivity of 100% (95% CI 99.2–100) and specificity of 92% (89.0–94.2) are quoted here as reported by Bhatt et al. 2009, below; the 2002 paper was not opened.
Bhatt M, Joseph L, Ducharme FM, Dougherty G, McGillivray D. Prospective validation of the Pediatric Appendicitis Score in a Canadian pediatric emergency department. Acad Emerg Med. 2009;16(7):591–596 — 246 children aged 4 to 18 at the Montreal Children’s Hospital, 34% with appendicitis (full text read).
Goldman RD, Carter S, Stephens D, et al. Prospective validation of the Pediatric Appendicitis Score. J Pediatr. 2008;153(2):278–282 — 849 children aged 1 to 17 in a Toronto tertiary paediatric emergency department. Read as the Evid Based Med. 2009;14(1):26 structured abstract and as reported by Bhatt et al. 2009; the 2008 paper was not opened.
Review of the Pediatric Appendicitis Score. MDCalc (accessed 10 October 2026) — the item table reproduced here, corroborated against Radiopaedia’s Paediatric appendicitis score article and Dhruv KK et al. Int Surg J. 2016;3(1):84–89.

Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/