Synopsis
Recognise delayed food-allergic gastrointestinal phenotypes, distinguish them from immediate IgE allergy and common infant disorders, and confirm diagnosis with time-limited elimination followed by planned reintroduction while protecting growth.
- Non-IgE gastrointestinal allergy causes symptoms hours to days after ingestion and is diagnosed clinically; skin-prick and specific-IgE tests are usually negative and do not confirm the mechanism.
- Common phenotypes are allergic proctocolitis, enteropathy and FPIES; record age, trigger, delay, reproducibility, stool, growth and systemic state rather than using one umbrella label.
- For suspected mild to moderate non-IgE cow's-milk allergy, use a two- to six-week supervised elimination followed by planned reintroduction to confirm that improvement was food-specific.
- Continue breastfeeding; maternal cow's-milk elimination is used only when the breastfed infant is symptomatic and should include dietetic calcium and vitamin D planning.
- For formula-fed infants, an extensively hydrolysed formula is generally first choice; amino-acid formula is reserved for severe disease, faltering growth, multiple allergy or failure of an adequate hydrolysed trial.
- Do not use lactose-free formula for cow's-milk protein allergy because it still contains cow's-milk protein, and avoid goat or sheep milk because proteins cross-react.
- Acute FPIES typically causes repetitive vomiting, pallor and lethargy one to four hours after food without urticaria or wheeze; treat fluids and physiology urgently.
- No broad allergy panel diagnoses delayed allergy, and food-specific IgG or atopy patch testing should not be used.
- Reintroduction is part of diagnosis and later tolerance assessment; home milk ladder is for selected low-risk non-IgE disease, never previous FPIES or immediate reactions without specialist direction.
- Plot weight and length, protect dietary variety and stop exclusions that fail to improve symptoms within the agreed trial.
Key red flags
Bilious vomiting, abdominal distension, guarding, haematemesis or shock requires urgent surgical and medical assessment before an allergy label.
Faltering growth, oedema, persistent diarrhoea, anaemia or hypoalbuminaemia indicates important enteropathy and needs early paediatric and dietetic review.
Repetitive delayed vomiting with pallor and lethargy after a specific food suggests FPIES even when skin tests are negative and no hives occur.
Immediate urticaria, angioedema, wheeze or collapse indicates an IgE-mediated mechanism and changes testing and emergency planning.
Blood in stool with fever, severe pain, travel or systemic illness needs infection, inflammatory bowel and surgical assessment rather than empirical milk exclusion alone.
Multiple prolonged food exclusions, homemade nutritionally incomplete formula or poor feeding can cause avoidable malnutrition and requires urgent dietetic correction.
Investigation priorities
Identify a reproducible delayed food relationship, phenotype, severity and nutritional effect.
Management branches
Delayed repetitive vomiting causes lethargy, poor perfusion or dehydration.
- Use ABCDE, monitor, obtain vascular access and check glucose, gas and electrolytes.
- Give rapid isotonic crystalloid and repeat according to perfusion under paediatric guidance.
- Exclude sepsis and surgical disease while documenting the exact food and delay.