Differentials
Physiological gastroesophageal reflux
SIGNS / SYMPTOMS
Recurrent vomiting in the absence of other symptoms, with normal exam and growth.
Regurgitation is more common after meals, and when the infant is in a recumbent position.
INVESTIGATIONS
No diagnostic tests are required.
Caregiver education and reassurance should be offered.
Malrotation with intermittent volvulus
SIGNS / SYMPTOMS
Bilious vomiting.
INVESTIGATIONS
Upper gastrointestinal contrast study may be used to demonstrate abnormal anatomy.
Abdominal ultrasound can demonstrate abnormal orientation of superior mesenteric vessels.
Intermittent intussusception
SIGNS / SYMPTOMS
Vomiting and abdominal pain may be associated with pallor and passage of red "currant jelly" stools.
Abdominal mass may be palpable.
INVESTIGATIONS
Abdominal ultrasound demonstrates telescoping of the bowel wall.
Air enema demonstrates telescoping of bowel and may be therapeutic.
Hirschsprung disease
SIGNS / SYMPTOMS
Vomiting may be preceded by abdominal distension and constipation.
A history of constipation back to neonatal period is usually reported, and there may have been delayed passage of meconium.
INVESTIGATIONS
Rectal biopsy demonstrates absence of ganglionic cells.
Pyloric stenosis
SIGNS / SYMPTOMS
Recurrent, projectile, nonbilious vomiting, typically in a 3- to 6-week old infant. May be palpable upper abdominal mass on exam.
INVESTIGATIONS
Abdominal ultrasound demonstrates thickened pyloric muscle with increased pyloric canal length.
Gastroenteritis
SIGNS / SYMPTOMS
Acute change in bowel habit and/or onset of vomiting.
May have had exposure to people with similar symptoms, recent foreign travel, or recent dietary change.
INVESTIGATIONS
Fecal sample for virology studies, microscopy, and culture help to identify causative organism.
Fecal-reducing substances are positive in lactose intolerance secondary to infectious gastroenteritis.
Hydrocephalus
SIGNS / SYMPTOMS
Vomiting associated with altered alertness, change in head circumference, bulging fontanel, splayed sutures, and "sun setting" of the eyes.
INVESTIGATIONS
Cranial ultrasound as initial test for rapid assessment, followed by CT or MRI to guide neurosurgical management.
Subdural hematoma
SIGNS / SYMPTOMS
Vomiting associated with altered level of alertness.
Other signs of nonaccidental injury such as bruising should be sought.
INVESTIGATIONS
CT head shows subdural fluid collection.
Further investigations for nonaccidental injury should be considered, including skeletal survey and multidisciplinary review.
Intracranial mass lesion
SIGNS / SYMPTOMS
Vomiting associated with altered level of alertness, seizures, or abnormal neurologic exam.
Signs of hydrocephalus may be evident.
INVESTIGATIONS
CT head shows lesion.
Infection
SIGNS / SYMPTOMS
Vomiting and altered feeding are more acute in nature.
Associated with fever, tachypnea, tachycardia, altered level of consciousness (increased irritability or lethargy), bulging fontanel, rash, high-pitched cry.
Signs of otitis media include tense, bulging tympanic membrane, but this can be difficult to visualize in small infants.
INVESTIGATIONS
Differentiating tests depend on severity and type of symptoms, and age at presentation.
Diagnostic tests include CBC with differential, blood cultures, blood sugar, blood lactate, inflammatory markers such as procalcitonin and C-reactive protein, baseline renal and liver function, urinalysis plus culture, lumbar puncture with cerebrospinal fluid virology, microscopy, and culture where indicated.
Metabolic conditions
SIGNS / SYMPTOMS
Considered when symptoms begin after mild illness and period of decreased oral intake.
Prolonged jaundice in neonate should be investigated for galactosemia.
INVESTIGATIONS
Tests include serum amino acid profile, lactate and ammonia, urinary organic acid profile.
Gal-1-PUT (galactose-1-phosphate uridyltransferase) assay in galactosemia.
Renal failure
SIGNS / SYMPTOMS
May have history of abnormal renal scans prenatally, or family history of renal disease.
May appear anemic and yellow-tinged.
Renal masses may be palpable.
Hypertension may be present.
INVESTIGATIONS
Renal function tests, blood gas to check pH and bicarbonate levels.
Urinalysis shows hematuria and/or proteinuria.
Renal ultrasound scan shows small kidney size, presence of obstruction/hydronephrosis, or kidney stones.
Poisoning
SIGNS / SYMPTOMS
Usually more acute presentation.
Vomiting may be associated with altered consciousness level, seizures, or altered neurologic exam.
Social history, to include living environment, exposure to hazardous materials, and contact with medications in the home, may reveal source of poison.
INVESTIGATIONS
Dictated by history and possible poison.
May include blood tests to check for pancytopenia, altered liver and renal function, toxin levels.
ECG may be indicated to identify arrhythmias.
Further investigation/management as advised by Poisons Unit.
Use of this content is subject to our disclaimer