eMedicine Specialties > Emergency Medicine > Pediatric

Pediatrics, Pyloric Stenosis: Differential Diagnoses & Workup

Author: Jagvir Singh, MD, Director, Division of Pediatric Emergency Medicine, Lutheran General Hospital of Park Ridge
Coauthor(s): Dara A Kass, MD, Clinical Assistant Instructor, Department of Emergency Medicine, State University of New York Downstate Medical Center, Kings County Hospital; Richard Sinert, DO, Associate Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, State University of New York College of Medicine; Consulting Staff, Department of Emergency Medicine, Kings County Hospital Center
Contributor Information and Disclosures

Updated: Jan 22, 2008

Differential Diagnoses

Adrenal Insufficiency and Adrenal Crisis
Pediatrics, Urinary Tract Infections and Pyelonephritis
Gastroenteritis
Renal Failure, Acute
Pediatrics, Dehydration
Pediatrics, Gastroenteritis
Pediatrics, Inborn Errors of Metabolism

Other Problems to Be Considered

Malrotation
Gastroesophageal reflux
Pyloric atresia
Pyloric antral web
Pyloric diaphragm
Poor feeding practices
Hiatal hernia
Congenital adrenal hyperplasia (CAH)

Workup

Laboratory Studies

  • Electrolytes, pH, BUN, and creatinine levels should be drawn at the time of obtaining intravenous access.
    • Hypochloremic, hypokalemic metabolic alkalosis is the classic electrolyte and acid-base imbalance of pyloric stenosis. Persistent emesis causes progressive loss of fluids rich in hydrochloric acid, which causes the kidneys to retain hydrogen ions in favor of potassium. Electrolyte abnormalities are dependent on the duration of symptoms in the affected infant.
    • The dehydration may result in hypernatremia or hyponatremia and may result in prerenal renal failure.
  • Elevated unconjugated bilirubin level may be present.

Imaging Studies

  • If the clinical presentation is typical and an olive is felt, the diagnosis is confirmed and further imaging is not warranted.
  • Ultrasonography is the imaging modality of choice when evaluating a child for IHPS. It is both highly sensitive (90-99%) and specific (97-100%) in the hands of a qualified sonographer. The pylorus is viewed in longitudinal and transverse planes. The sonographic hallmark of IHPS is the thickened pyloric muscle.
  • Criteria for making the diagnosis include pyloric muscle thickness greater than 4 mm. The length of the pyloric canal is variable and may range from 14 mm to 20 mm. The pyloric diameter may range from 10-14 mm.
    • IHPS may be falsely diagnosed in infants who have pylorospasm. Ultrasonography also allows for observation of peristaltic activity, differentiating between pylorospasm and true IHPS.
    • Upper gastrointestinal imaging (UGI) can help to confirm the diagnosis of IHPS, but it is not routinely performed unless ultrasonography is nondiagnostic.
  • The "shoulder" sign is a collection of barium in the dilated prepyloric antrum and may be seen in the infant with IHPS. The "double track" sign, two thin tracks of barium compressed between thickened pyloric mucosa, once thought to be pathognomonic of IHPS, has recently been identified in multiple cases of sonographically confirmed pylorospasm.

Procedures

  • Upper GI endoscopy has been used as an adjunct diagnostic tool in select cases of IHPS when other imaging tests are inconclusive or when the infant presents with atypical clinical features.

More on Pediatrics, Pyloric Stenosis

Overview: Pediatrics, Pyloric Stenosis
Differential Diagnoses & Workup: Pediatrics, Pyloric Stenosis
Treatment & Medication: Pediatrics, Pyloric Stenosis
Follow-up: Pediatrics, Pyloric Stenosis
References
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References

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  3. Leclair MD, Plattner V, Mirallie E, Lejus C, Nguyen JM, Podevin G. Laparoscopic pyloromyotomy for hypertrophic pyloric stenosis: a prospective, randomized controlled trial. J Pediatr Surg. Apr 2007;42(4):692-8. [Medline].

  4. van den Ende ED, Allema JH, Hazebroek FW, Breslau PJ. Can pyloromyotomy for infantile hypertrophic pyloric stenosis be performed in any hospital? Results from two teaching hospitals. Eur J Pediatr. Jun 2007;166(6):553-7. [Medline].

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Further Reading

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Keywords

pyloric stenosis in children, pyloric stenosis in infants, pyloric stenosis, intestinal obstruction in infancy, intestinal obstruction in infants, gastric outlet obstruction, infantile hypertrophic pyloric stenosis, IHPS

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Contributor Information and Disclosures

Author

Jagvir Singh, MD, Director, Division of Pediatric Emergency Medicine, Lutheran General Hospital of Park Ridge
Jagvir Singh, MD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.

Coauthor(s)

Dara A Kass, MD, Clinical Assistant Instructor, Department of Emergency Medicine, State University of New York Downstate Medical Center, Kings County Hospital
Dara A Kass, MD is a member of the following medical societies: American College of Emergency Physicians, Emergency Medicine Residents Association, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Richard Sinert, DO, Associate Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, State University of New York College of Medicine; Consulting Staff, Department of Emergency Medicine, Kings County Hospital Center
Richard Sinert, DO is a member of the following medical societies: American College of Physicians and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Garry Wilkes, MBBS, FACEM, Director of Emergency Medicine, Bunbury Health Service, Western Australia Country Health Service; Adjunct Associate Professor, School of Exercise, Biomedical and Health Sciences, Faculty of Computing, Health and Science, Edith Cowan University; Medical Director, St John Ambulance Service
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc
Disclosure: Pfizer Inc Stock Investment from broker recommendation; Avanir Pharma Stock Investment from broker recommendation

Managing Editor

Grace M Young, MD, Associate Professor, Department of Pediatrics, University of Maryland Medical Center
Grace M Young, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Emergency Physicians
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Richard G Bachur, MD, Assistant Professor of Pediatrics, Harvard Medical School; Associate Chief and Fellowship Director, Attending Physician, Division of Emergency Medicine, Children's Hospital of Boston
Richard G Bachur, MD is a member of the following medical societies: American Academy of Pediatrics, Society for Academic Emergency Medicine, and Society for Pediatric Research
Disclosure: Nothing to disclose.

 
 
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