Suspected appendicitis in children
pARC · Pediatric Appendicitis Risk Calculator ; PAS · Pediatric Appendicitis Score.
pARC — paediatric appendicitis risk
Enter all eight observations from the same assessment.
Emergency department · 5–18 completed years · Pain for less than 96 h
Population and exclusions
Suspected appendicitis in the emergency department · 5–18 completed years · pain <96 h. Excludes pregnancy, previous abdominal surgery, inflammatory bowel disease, chronic pancreatitis, sickle cell disease, cystic fibrosis, unreliable history due to a medical condition or abdominal trauma within the previous 7 days.
Interpreting results
- Low risk · <5%
- Observation with reassessment may be considered according to the clinical findings.
- Low risk · 5–<15%
- Observation with reassessment may be considered according to the clinical findings.
- Intermediate risk · 15–<25%
- Observation with reassessment may be considered. The need for imaging depends on the clinical findings and course.
- Intermediate risk · 25–<50%
- Further assessment depends on the clinical examination, course and care pathway.
- Intermediate risk · 50–<75%
- Further assessment depends on the clinical examination, course and care pathway.
- Intermediate risk · 75–<85%
- Further assessment depends on the clinical examination, course and care pathway.
- High risk · ≥85%
- Surgical evaluation may be considered, with selective imaging according to the clinical findings.
Method and limitations
Bands use the unrounded probability. Male sex contributes separately from the age group. Girls aged 12 years and older and boys aged 14 years and older have a zero age contribution. Bands are descriptive and do not prescribe management. Low, intermediate and high categories follow Table 4 of the original publication, retaining all seven bands. Original model developed in paediatric emergency departments; community recalibration is not applied here. No local validation is established. Complete observations do not certify eligibility: respect exclusions and reassess according to the clinical course. Low risk does not exclude appendicitis. The result is not an automatic diagnosis.
Formula and logic
pARC = 100 / (1 + exp(−S)). S = intercept + contributions of sex, age group, duration, the four signs and absolute neutrophil count. ANC <14 G/L: 1.7734 × √ANC; ANC ≥14 G/L: 6.6195.
Inputs and original units
- Absolute neutrophil count (ANC) · G/L
- Absolute laboratory concentration for this assessment. Neither total white cells nor a percentage. Explicit zero is accepted; censored or unknown values prevent calculation. Up to 6 entered decimal places, without prior rounding.
Sources
- Kharbanda AB et al. — Development and Validation of a Novel Pediatric Appendicitis Risk Calculator (pARC)
2018 · Original ED model development, variables, population and risk strata.
- Cotton DM et al. — Validation of the Pediatric Appendicitis Risk Calculator (pARC) in a Community Emergency Department Setting
2019 · Prospective community validation. The described recalibration is not applied in this tool.
Definition version : 1.0.2
Pediatric Appendicitis Score (PAS)
Sum of eight clinical and laboratory criteria; total 0–10.
Original Samuel 2002 version · 4–15 years
Population and exclusions
Suspected appendicitis in children aged 4 to 15 years, the population studied in 2002. Original variant, distinct from Alvarado and later PAS pathways.
Interpreting results
The score alone neither confirms nor excludes appendicitis. Examination, course and reassessment remain necessary; no automatic indication for imaging, intervention or discharge. The original does not set a numeric threshold for fever or neutrophilia; no additional threshold or severity band is invented.
Method and limitations
The score alone neither confirms nor excludes appendicitis. Examination, course and reassessment remain necessary; no automatic indication for imaging, intervention or discharge. The original does not set a numeric threshold for fever or neutrophilia; no additional threshold or severity band is invented.
Formula and logic
Sum of explicit contributions, without prior rounding.
Inputs and original units
- White blood cells (WBC) · G/L
- ≥10 G/L = ≥10 000/mm³; equality included, original Table 2.
Polymorphonuclear neutrophilia — Clinical/laboratory criterion in the original; no absolute or percentage threshold specified. No result = missing, not No.
Sources
- Samuel · Journal of Pediatric Surgery — Pediatric Appendicitis Score
2002 · Original study, children 4–15 years; eight criteria, two weighted 2; white blood cells ≥10 000/mm³ (Table 2).
- Samuel · copie institutionnelle University of Florida — Pediatric Appendicitis Score · texte intégral et Tableau 2
2002 · Visual reading of the threshold ≥10 000; fever and neutrophilia without a defined numeric threshold in the original.
Definition version : 0.1.0