FPIES

What is the food protein-induced enterocolitis (FPIES)?

Vomiting associated with the FPIES Syndrome

Food Protein-Induced Enterocolitis Syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity. It is under-recognised, frequently misdiagnosed, and characterised by severe, repetitive vomiting and/or protracted diarrhoea.

The vomiting is a striking feature; it is protracted and ongoing, often associated with vomiting dark green bile. Abnormal stools can be associated. Symptoms typically begin 1 to 4 hours after ingestion. This vomiting spell may then be followed by a floppy, grey or limp baby, sometimes described as a rag-doll appearance, terrifying to all. The patient then thankfully returns to normal health (unlike with viral gastroenteritis or food poisoning).

Unlike immediate IgE-mediated allergies, FPIES does not manifest with hives, angioedema, or respiratory symptoms, and standard diagnostic tests (skin prick tests, specific IgE blood tests) are typically negative. Clinicians establish the diagnosis through a detailed clinical history or a supervised oral food challenge.

Clinical Presentation & Risk of Misdiagnosis

Reactions range from mild (non-dehydrating vomiting/diarrhoea) to severe, potentially causing dehydration and shock

Diagnostic Pitfall: Profuse vomiting, lethargy, pallor, and resultant acidosis can closely mimic acute sepsis and other neurological or cardiac presentations.
Clinical Consequence: Without a detailed dietary history, recurrent reactions are frequently misdiagnosed as repeated episodes of sepsis, leading to avoidable intensive care admissions.

Common Triggers

Infants: Cow's milk, soy, rice, oats, and legumes (though any food protein can act as a trigger).
Older Children and Adults: Fish and shellfish.

Management & Safety

Avoidance: Strict elimination of the causal protein is the usual approach, although we are able to discuss slow, home-based, dietitian-supervised microdosing to try to expedite the anticipated tolerance. ,
Acute Management: Focus on fluid resuscitation and preventing dehydration. Ondansetron is commonly utilised to manage acute protracted vomiting.
Adrenaline: Not indicated, as FPIES does not cause anaphylaxis.

Prognosis

FPIES is typically outgrown in early childhood, with most patients achieving tolerance by 3 years of age.

Clinic Expertise

Our specialist allergy clinic has extensive experience diagnosing and managing FPIES. Prof du Toit has published peer-reviewed research on the condition. We offer specialist consultation and supervised oral food challenges for diagnostic confirmation.

Here are key academic publications on Food Protein-Induced Enterocolitis Syndrome (FPIES) involving Dr George du Toit:

Oral Food Challenge Guidelines: Bird, J. A., Barni, S., Brown-Whitehorn, T. F., du Toit, G., Infante, S., & Nowak-Wegrzyn, A. (2021). Food protein-induced enterocolitis syndrome oral food challenge: Time for a change? Annals of Allergy, Asthma & Immunology, 126(5), 506–515.PubMed Abstract
British Isles Population & Surveillance Study: Stiefel, G., Alviani, C., Afzal, N. A., Byrne, A., du Toit, G., DunnGalvin, A., et al. (2022). Food protein-induced enterocolitis syndrome in the British Isles. Archives of Disease in Childhood, 107(2), 123–127.BPSU Overview & References
UK Clinical Presentation and Referral Characteristics: Ludman, S., Harmon, M., Whiting, D., & du Toit, G. (2014). Clinical presentation and referral characteristics of food protein-induced enterocolitis syndrome in the United Kingdom. Annals of Allergy, Asthma & Immunology, 113(3), 290–294.PubMed Abstract
FPIES Review: van der Poel, L. A., Fox, A., & Du Toit, G. (2009). Food Protein-Induced Enterocolitis Syndrome: A Review. Current Allergy & Clinical Immunology, 22(2), 56–57.The FPIES Foundation Toolbox