Appendicitis is the most common condition in children requiring emergency abdominal surgery. Delayed or missed diagnosis in young children is common and is associated with increased rates of perforation. Although several scoring systems have been developed, there is still no consensus on clinical, laboratory, and imaging criteria for diagnosing appendicitis. This issue reviews key age-based historical and physical examination findings, as well as clinical scoring systems, that can help guide the workup of appendicitis in children. The existing literature is reviewed to provide guidance for the management of children with appendicitis, including recommendations for diagnostic studies, prophylactic antibiotics, pain medication, and surgical consultation.
An 11-year-old previously healthy boy presents to the ED on a busy Saturday evening. He has acute abdominal pain that started 18 hours ago as diffuse periumbilical abdominal pain. Within the last 3 hours or so, the pain migrated to the right lower quadrant and worsened in severity. The child says the bumps on the car ride to the hospital were painful, and hopping up and down makes the pain worse. He says it seems to be a bit better when he lies still and does not move. Oral ibuprofen has not really helped the pain. The patient has not eaten a meal all day and has vomited 3 times today. On presentation, he has a temperature of 38.3°C (101°F). He is fully immunized and does not have any upper respiratory symptoms. He has never had similar pain in the past and has no history of previous abdominal surgeries. He has a normal genitourinary examination. He has obvious discomfort with palpation of his abdomen with maximum tenderness in the right lower quadrant. He exhibits guarding and rebound tenderness. His mother asks you whether this could be appendicitis, and whether he will need surgery. You begin to think… Is this appendicitis? What else could it be? How will you definitively determine the diagnosis? What laboratory evaluation and imaging tests should you order? It is now 2:00 AM. If the patient definitely has appendicitis, does he need an emergent appendectomy or can it wait?
Your next patient is a 16-year-old girl with abdominal pain who is brought into the ED by her mother. When the girl arrived to the ED, her vital signs were age-appropriate except for tachycardia, with a heart rate of 115 beats/min. Initially, she had some mild pain in her lower abdomen that gradually got worse. What is your differential diagnosis? What history, physical examination findings, or diagnostic evaluations should you obtain?
Your last patient of the evening is a 4-year-old boy with abdominal pain who is brought into the ED by his parents. The parents report that the boy was at his baseline state of health until 2 days ago when he became more fatigued and did not want to play as much. Today, he has had poor oral intake and spiked a fever to 38.6°C (101.5°F). The patient has been moaning and seems to grab at his abdomen in pain. Again, the diagnosis of appendicitis comes to mind. Is the rate of perforated appendicitis higher in this age group? How do you get an accurate history and perform a physical examination if the child will not talk to you and cowers behind his father when you approach him?
Abdominal pain is a common chief complaint for pediatric patients presenting to an emergency department (ED) and, most of the time, the etiology is self-limited and nonemergent. Nonetheless, acute appendicitis must be considered in the differential diagnosis of abdominal pain in the pediatric population because missed acute appendicitis can lead to morbidity and mortality as well as medicolegal consequences.
In children, acute appendicitis is the most common condition requiring emergency surgery, with > 75,000 children diagnosed annually in the United States.1 The potential for morbidity and mortality from perforation of the appendix necessitates prompt diagnosis.2 Although a variety of clinical scoring systems have been developed, there is still no consensus on clinical, laboratory, and imaging criteria for diagnosing appendicitis, which poses a dilemma for the emergency clinician.3-5
This issue of Pediatric Emergency Medicine Practice reviews the existing literature to help develop strategies for the diagnosis and management of appendicitis in the pediatric population.
A literature search was performed in PubMed using the search terms appendicitis, abdominal pain, pediatrics, clinical scoring systems, ultrasound, diagnostic tests, radiation risk, and non-operative management. An English language filter was applied, and articles were sorted by relevance. Several thousand articles were found, with over 1000 screened by title, then abstract. A total of 101 articles were chosen for inclusion.
There are many deficiencies inherent to the quality of the literature, including the lack of pediatric studies and more retrospective studies. According to standard evidence-level scales, the majority of evidence for pediatric appendicitis falls into the “weak” or “moderately strong” categories, and there are many single-center studies with limited enrollment. There is an article from the Effective Health Care Program on the “Diagnosis of Right Lower Quadrant Pain and Suspected Appendicitis” in the National Guidelines Clearinghouse.6 Despite these studies, there is no clear consensus on the approach to the pediatric patient with abdominal pain.
1. “I saw this patient in the ED 2 days ago. He presented with 2 hours of vague abdominal pain, and his exam was not consistent with acute appendicitis. I can't believe he is back today with a perforated appendix.”
Early appendicitis can present with vague abdominal pain with a broad differential diagnosis. Therefore, it can be easy to miss early appendicitis. If a patient presents to the ED with < 24 hours of abdominal pain or the diagnosis is equivocal, close follow-up with a primary care provider or ED follow-up should be ensured if the patient’s symptoms persist.
8. “This 3-year-old boy seemed to have abdominal pain on exam, but he had a normal appendix ultrasound. He re-presented to the ED 2 days later with a large right-sided basilar pneumonia.”
The preverbal child can be difficult to examine in the ED. Even though it is true that children aged < 5 years with appendicitis often present with a perforated appendix, other diagnoses are much more common in this age group and should be considered. Failing to consider a broad differential may result in missed pathology.
9. “I decided to withhold morphine from my 8-year-old patient with suspected appendicitis. I didn’t want to miss a diagnosis because I administered an analgesic.”
Early analgesia is recommended. There is no increase in missed appendicitis or in negative appendectomies after analgesia. Adequate pain control for patients with suspected appendicitis in the ED is imperative.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study is included in bold type following the reference, where available. In addition, the most informative references cited in this paper, as determined by the author, are highlighted.
Why to Use
The PAS has been validated in multicenter studies and may be as good as clinician gestalt at identifying patients who are at low risk for appendicitis versus patients with appendicitis.
When to Use
Use the PAS for children and adolescents who present with acute abdominal pain in whom appendicitis is suspected, especially if the pain is localized to the right lower quadrant.
Low Risk PAS (< 4 points)
Equivocal PAS (4-6 points)
High Risk PAS (≥ 7 points)
Jamie Lovell, MD
Patients who are identified as not low risk (eg, equivocal or high risk) for appendicitis by the PAS should receive nothing by mouth, and the next steps should include administration of intravenous fluids and analgesia, ordering imaging, and/or surgical consultation.
Patients in the low risk group according to the PAS do not have no risk for appendicitis. Emergency clinicians should use clinical discretion to determine if imaging or surgical consultation would help with diagnosis for these patients.
The PAS was developed in 2002 by Dr. Madan Samuel in a prospective cohort study of 1170 patients
aged 4 to 15 years who presented with abdominal pain. Clinical history, physical examination, and laboratory data for these patients were analyzed to identify 8 variables that showed statistical significance for acute appendicitis. A 10-point scoring system was created using these variables.
The PAS has been validated in multiple prospective studies. Bhatt et al (2009) studied 246 children aged 4 to 18 years and found a sensitivity of 97.6%, with a negative predictive value of 97.7%, at a cutoff PAS of ≤ 4 points. When a PAS of ≥ 8 points was used to determine that appendectomy was needed, the specificity was 95.1% and the positive predictive value was 85.2%. In this cohort, 41% of computed tomography scans would have been avoided using the PAS. Goldman et al (2008) evaluated the PAS in 849 children aged 1 to 17 years; the area under the receiver operating characteristic curve was 0.95, although the study used more con-servative cutoffs of ≤ 2 points and ≥ 7 points.
Schneider et al (2007) evaluated both the PAS and the Alvarado score and found that they had similar sensitivity and specificity, but concluded that neither score was sufficient to be relied on as the only method to determine whether appendectomy is needed. Shah et al (2016) developed a diagnostic algorithm and used it prospectively in 840 patients, 267 of whom were ultimately diagnosed with appendicitis. The algorithm was found to have a sensitivity of 98.6% and specificity of 94.4%, with a decrease in utilization of computed tomography from 75.4% to 24.2%.
Madan Samuel, MD
Why to Use
Acute appendicitis is a common surgical emergency in the United States. Diagnostic accuracy for appendicitis is increased with the use of CT scanning; however, there are risks and disadvantages associated with CT scans, including radiation exposure, contrast-related complications, and cost. The Alvarado score is a well-established and widely used clinical decision tool that may help reduce the need for CT scans when diagnosing appendicitis.
When to Use
The Alvarado score can be used for patients with suspected acute appendicitis (typically, patients presenting with right lower quadrant pain).
Ayomide Loye, MD
Xiao Chi Zhang, MD, MS
Clinicians should use clinical judgment in nonclassic presentations of appendicitis.
The Alvarado score was initially described in 1986 by Dr. Alfredo Alvarado in a retrospective study at a single center in Philadelphia. For 305 patients aged 4 to 80 years, 8 predictive factors were identified to stratify the risk of acute appendicitis. Increasing scores were found to correlate with increasing risk for appendicitis, as determined by final surgical pathology.
In 2007, McKay et al studied a retrospective cohort of 150 patients (aged ≥ 7 years) presenting with abdominal pain, with the aim of stratifying risk specifically for the use of computed tomography (CT) scanning for diagnosis. They found 35.6% sen-sitivity for appendicitis based on equivocal Alvarado scores (defined as scores of 4-6) compared with 90.4% sensitivity based on CT scan in this group. They concluded that patients with equivocal scores would benefit from CT scanning.
Similarly, Coleman et al (2018) conducted a retrospective review in which the Alvarado score was applied to a cohort of 492 patients (median age, 33 years), and found that 20% of the patients scores ≥ 9 in men or a score of 10 in women) or the low-risk group (scores ≤ 1 in men and ≤ 2 in women). These patients spent a cumulative total of > 170 hours awaiting CT scanning that was ultimately unnecessary. The authors found that scores of 0 or 1 had 0% incidence of acute appendicitis and that 100% of men with a score ≥ 9 and 100% of women with a score of 10 had acute appendicitis confirmed on surgical pathology.
Pogorelić et al (2015) prospectively studied 311 pediatric patients and applied both the Alvarado score and the pediatric appendicitis score (Samuel 2002). Receiver operating characteristic analysis showed similar accuracy between the scores, with area under the receiver operating characteristics of 0.74 (95% confidence interval, 0.66-0.82) for the Alvarado score and 0.73 (95% confidence interval, 0.65-0.81) for the pediatric appendicitis score. The authors concluded that the scores may be useful in emergency settings, but neither score is superior to the clinical gestalt of a pediatric surgeon.
Alfredo Alvarado, MD
Why to Use
The pARC may help determine the need for advanced imaging such as formal ultrasound or CT scan. It can identify low-risk patients who can be observed in the ED or discharged from the ED with follow-up or return precautions. In a validation study, the pARC formula performed better than the PAS by placing fewer patients into equivocal risk categories, making the pARC potentially more useful than the PAS for aiding clinical decision-making.
When to Use
Use the pARC in children aged ≥ 5 years who present to the ED or outpatient setting with acute abdominal pain with a duration < 96 hours. Patients with the following conditions were excluded from the pARC study:
Patients determined by the pARC to be at low risk for appendicitis can be considered candidates for safe discharge or observation in the ED without advanced imaging such as ultrasound or CT scan, based on the discretion of the emergency clinician and the comfort level of the patient’s family. Given the specificity of the pARC, patients who are classified as high or high-intermediate risk for appendicitis may not need advanced imaging. In the high-risk group, 1.2% of appendectomy specimens were negative for appendicitis on pathology analysis and in the high-intermediate risk group, 2.6% of the specimens were negative.
Derek Tam, MD, MPH
Hector Vazquez, MD
Critically ill patients or patients with emergent “surgical abdomens” (rigidity, visible ecchymosis or hematoma, etc) should not be considered for delayed surgical consultation or imaging. These patients will likely benefit from early consultation with pediatric surgeons and from imaging, if they are able to be transported to radiology.
The pARC formula was derived from a dataset of 2423 patients with an interquartile age range of 8 to 14 years. Candidate predictors with > 10% missing data were not included. Patients with certain comorbid conditions were also excluded (Kharbanda 2018).
While absolute neutrophil count (ANC) was used in the pARC formula, ANC values were missing for 216 (9%) of the patients in the derivation data set. For patients missing the ANC value, it was imputed as ANC = (-0.8783 + 1.1008 x sqrt(WBC))^2. For patients missing both ANC and white blood cell count values, the ANC value was imputed as 7 x 103/mcL, which was the mean ANC value in the derivation cohort. The proportion of missing values was less than the 10% cutoff point chosen by the study authors; however, imputation of missing values has the potential to introduce bias into the equation.
An independent validation study was conducted at different centers and demonstrated the ability of the pARC to outperform the pediatric appendicitis score (Cotton 2019). This study demonstrated a superior area under the receiver operating characteristic curve with nonoverlapping 95% confidence intervals as compared to the pediatric appendicitis score.
Manuel Mutschler, MD
Kharbanda AB, Vazquez-Benitez G, Ballard DW, et al. Development and validation of a novel pediatric appendicitis risk calculator (pARC). Pediatrics. 2018;141(4): e20172699.
Cotton DM, Vinson DR, Vazquez-Benitez G, et al. Validation of the pediatric appendicitis risk calculator (pARC) in a community emergency department setting. Ann Emerg Med. 2019. In press.
Callie Becker, MD; Anupam Kharbanda, MD, MS
Ran D. Goldman, MD; Kristy Williamson, MD
September 2, 2019
October 1, 2022
4 AMA PRA Category 1 Credits™, 4 ACEP Category I Credits, 4 AAP Prescribed Credits, 4 AOA Category 2-A or 2-B Credits.
Date of Original Release: September 1, 2019. Date of most recent review: August 15, 2019. Termination date: September 1, 2022.
Accreditation: EB Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. This activity has been planned and implemented in accordance with the accreditation requirements and policies of the ACCME.
Credit Designation: EB Medicine designates this enduring material for a maximum of 4 AMA PRA Category 1 CreditsTM. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Specialty CME: For more information, please call Customer Service at 1-800-249-5770.
ACEP Accreditation: Pediatric Emergency Medicine Practice is also approved by the American College of Emergency Physicians for 48 hours of ACEP Category I credit per annual subscription.
AAP Accreditation: This continuing medical education activity has been reviewed by the American Academy of Pediatrics and is acceptable for a maximum of 48 AAP credits per year. These credits can be applied toward the AAP CME/CPD Award available to Fellows and Candidate Fellows of the American Academy of Pediatrics.
AOA Accreditation: Pediatric Emergency Medicine Practice is eligible for up to 48 American Osteopathic Association Category 2-A or 2-B credit hours per year.
Needs Assessment: The need for this educational activity was determined by a survey of medical staff, including the editorial board of this publication; review of morbidity and mortality data from the CDC, AHA, NCHS, and ACEP; and evaluation of prior activities for emergency physicians.
Target Audience: This enduring material is designed for emergency medicine physicians, physician assistants, nurse practitioners, and residents.
Goals: Upon completion of this activity, you should be able to: (1) demonstrate medical decision-making based on the strongest clinical evidence; (2) cost-effectively diagnose and treat the most critical ED presentations; and (3) describe the most common medicolegal pitfalls for each topic covered.
Discussion of Investigational Information: As part of the journal, faculty may be presenting investigational information about pharmaceutical products that is outside Food and Drug Administration approved labeling. Information presented as part of this activity is intended solely as continuing medical education and is not intended to promote off-label use of any pharmaceutical product.
Faculty Disclosures: It is the policy of EB Medicine to ensure objectivity, balance, independence, transparency, and scientific rigor in all CME-sponsored educational activities. All faculty participating in the planning or implementation of a sponsored activity are expected to disclose to the audience any relevant financial relationships and to assist in resolving any conflict of interest that may arise from the relationship. Presenters must also make a meaningful disclosure to the audience of their discussions of unlabeled or unapproved drugs or devices. In compliance with all ACCME Essentials, Standards, and Guidelines, all faculty for this CME activity were asked to complete a full disclosure statement. The information received is as follows: Dr. Becker, Dr. Kharbanda, Dr. Goldman, Dr. Williamson, Dr. Mishler, Dr. Skrainka, Dr. Claudius, Dr. Horeczko, and their related parties report no significant financial interest or other relationship with the manufacturer(s) of any commercial product(s) discussed in this educational presentation.
Commercial Support: This issue of Pediatric Emergency Medicine Practice did not receive any commercial support.
Earning Credit: Two Convenient Methods: (1) Go online to www.ebmedicine.net/CME and click on the title of this article. (2) Mail or fax the CME Answer And Evaluation Form with your June and December issues to Pediatric Emergency Medicine Practice.
Hardware/Software Requirements: You will need a Macintosh or PC with internet capabilities to access the website.
Additional Policies: For additional policies, including our statement of conflict of interest, source of funding, statement of informed consent, and statement of human and animal rights, visit https://www.ebmedicine.net/policies.