Vomiting in Infancy: Is It FPIES?

Elizabeth Feuille, MD; Anna H. Nowak-Wegrzyn, MD, PhD


January 02, 2019

When Should You Suspect FPIES?

Diagnosis of FPIES is clinical, based on typical presenting signs and symptoms and time to symptom resolution (eg, in acute FPIES, symptoms resolve within hours from ingestion of the implicated food, and in chronic FPIES, symptoms resolve over a period of days). Other than an oral food challenge (OFC), there is no confirmatory test or specific biomarker for FPIES.[1] Diagnostic criteria from the international consensus guidelines aid the clinician in diagnosing FPIES. For chronic FPIES specifically, the diagnosis is presumptive without a confirmatory OFC.[1]

FPIES is a diagnosis of exclusion—one that requires a high index of suspicion. Diagnosing FPIES can be particularly challenging because of delays in symptom onset after exposure to a food trigger and implication of foods that are often considered hypoallergenic (for example, rice, oats, sweet potato). The differential diagnosis is also broad and includes very common conditions such as viral gastroenteritis or severe conditions such as sepsis.

What Are the Diagnostic Criteria for FPIES?

The first international consensus guidelines for diagnosis and management of FPIES created by the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology and the International FPIES Association advocacy group, were published in 2017. These guidelines outline specific diagnostic criteria for acute and chronic FPIES.[1]

The diagnostic criteria for chronic FPIES are based on the classic presenting symptoms of intermittent and progressive vomiting and/or diarrhea that develop in patients who ingest the suspect food on a regular basis; these symptoms also may be accompanied by failure to thrive, dehydration, and metabolic acidosis. The most important criterion for chronic FPIES is resolution of symptoms days after elimination of the suspect food and recurrence of vomiting 1-4 hours after the food trigger is reintroduced. The diagnosis of chronic FPIES is presumptive without a confirmatory challenge.

Per the international consensus guidelines[1] for acute FPIES, presentation should meet the following mandatory criterion and three of the minor criteria:

Mandatory Criterion

  • Vomiting in the 1-4 hour period after ingestion of the suspect food and absence of classic IgE-mediated allergic skin or respiratory symptoms

Minor Criteria

  • Repetitive vomiting after the same food

  • Repetitive vomiting 1-4 hours after a different food

  • Extreme lethargy with any reaction

  • Marked pallor with any reaction

  • ED visit with suspected reaction

  • Need for IV fluids with suspected reaction

  • Diarrhea within 24 hours (usually 5-10 hours)

  • Hypotension

  • Hypothermia


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