FPIES (Food Protein-Induced Enterocolitis Syndrome) is a non-IgE-mediated food allergy that mainly causes gastrointestinal symptoms such as vomiting, diarrhoea and lethargy. It can be difficult to diagnose because standard allergy tests do not detect it, but most children eventually outgrow the condition.
Even in more severe cases, FPIES does not cause anaphylaxis as it is not that type of allergy. Instead, reactions usually involve gastrointestinal symptoms such as vomiting and diarrhoea.
Many children with FPIES have only one trigger food, although some react to more than one. Encouragingly, we know that most children eventually outgrow FPIES.
Treatment for FPIES
Allergy London is now offering children an emerging treatment approach involving the gradual, carefully controlled reintroduction of trigger foods over several months. Developed by a specialist team at BC Children’s Hospital in Vancouver, early experience suggests that many children can progress towards eating their trigger food freely within 9–12 months, with reactions during treatment typically being mild.
Treatment is offered following specialist assessment, shared decision-making and an individualised treatment plan.
Find out more within Allergy London’s ‘FPIES Treatment‘ section.
Written by
Professor Adam Fox
Date written: August 2026
Adam Fox is a Professor of Paediatric Allergy with over 20 years experience in both the NHS and private sector. Professor Fox is Commercial Medical Director at Guy’s & St Thomas’ Hospitals NHS Foundation Trust and Professor of Paediatric Allergy at King’s College London and the founding Director of the KCL Allergy Academy, a postgraduate educational programme, which was a finalist at the BMJ Awards in 2018.
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