An Infant With Acute FPIES: The New Guidelines

Stephanie A. Leonard, MD


August 09, 2017

Case Presentation: An Infant With Repetitive Vomiting

A 7-month-old breastfed female infant (born at term) presents with a history of repetitive vomiting. The patient was well until age 5 months, when she ingested oat cereal mixed with breast milk, something she had tolerated twice in the past. This time, 2 hours after ingesting a couple of spoonfuls, she developed multiple episodes (> 10) of vomiting over 6 hours.

Her parents describe her as looking pale and report that she had one loose stool. There was no hematemesis or hematochezia. The week before this episode, the infant had received her 4-month vaccines, and she had had symptoms of an upper respiratory infection.

At the time of vomiting, there was no fever, upper respiratory symptoms, or history of sick contacts. She did not have a rash or any respiratory distress. There is a family history of allergic rhinitis, but no other significant birth or medical history.

The infant's parents took her to the emergency department, where her initial exam was benign except that she appeared tired. Her vital signs were as follows: heart rate, 133 beats/min; temperature, 99.7°F; respiratory rate, 34 breaths/min; and oxygen saturation, 98%. She received a normal saline bolus, and testing was performed. Laboratory tests performed about 6 hours after the vomiting began showed neutrophilia, a mildly increased chloride value, mild transaminitis, and mild hyperalbuminemia (Table).

Table. Lab Test Results

Test Result Reference Range
C-reactive protein 0.60 mg/dL 0.00-0.99 mg/dL
Comprehensive Metabolic Panel
Sodium 142 mmol/L 131-145 mmol/L
Potassium 4.5 mmol/L 3.7-5.9 mmol/L
Chloride 109 mmol/L 98-108 mmol/L
CO2 22 mmol/L 18-27 mmol/L
Anion gap 11 mmol/L 5-20 mmol/L
BUN 11 mg/dL 4-18 mg/dL
Creatinine 0.29 mg/dL 0.05-0.60 mg/dL
BUN/creatinine ratio 37.9  
Calcium 9.7 mg/dL 9.0-11.0 mg/dL
Albumin/globulin ratio 2.3  
AST 64 U/L 20-60 U/L
ALT 52 U/L 5-48 U/L
Alkaline phosphatase 225 U/L 145-320 U/L
Glucose 105 mg/dL 50-110 mg/dL
Total protein 5.9 g/dL 5.4-7.0 g/dL
Albumin 4.1 g/dL 2.6-3.6 g/dL
Total bilirubin 0.4 mg/dL 0.1-1.0 mg/dL
Complete Blood Count
White blood cells 25.4 µL 4.0-12.0 µL
Red blood cells 4.71 106/µL 3.80-5.40 106/µl
Hemoglobin 12.4 g/dL 10.5-14.0 g/dL
Hematocrit 37.2% 32.0-42.0 %
MCV 78.9 fL 72.0-88.0 fL
MCH 26.3 pg 24.0-30.0 pg
MCHC 33.4% 32.0-36.0 %
RCDW 11.9 RDW units 11.6-16.0 RDW units
Platelets 415 µL 140-440 µL
MPV 7.3 fL 6.0-9.5 fL
Manual Differential
Segmented neutrophils 65% 15-45 %
Band neutrophils 6% 0 – 10%
Lymphocytes 19% 35-70 %
Monocytes 9% 2-12 %
Eosinophils 1% 0-5 %
Absolute neutrophil count 18,034 µL 1100-5500 µL
ALT = alanine aminotransferase; AST = aspartate aminotransferase; BUN = blood urea nitrogen; MCH = mean corpuscular hemoglobin; MCHC = mean corpuscular hemoglobin concentration; MCV = mean corpuscular volume; MPV = mean platelet volume; RCDW = red cell distribution width

The rest of the complete blood count, electrolyte panel, and C-reactive protein results were within normal limits. Fecal lactoferrin and occult blood tests were positive. Urinalysis and cultures (blood, urine, and stool) were negative. Imaging, including abdominal radiography, abdominal ultrasound, and an upper gastrointestinal study, was normal.

The patient was admitted for bilious vomiting and stabilized after intravenous (IV) fluids were administered. The next morning, the patient was back to baseline and tolerating breast milk. A challenge to oatmeal was performed, and after 2 hours, she developed multiple episodes of vomiting that lasted about 1 hour. Oat food protein-induced enterocolitis syndrome (FPIES) was diagnosed, and the patient was discharged.


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