Food Allergy


General points:

  • The most common food allergens for children (>95% cases) are milk, egg, peanut, tree nuts, white fish, wheat and sesame.  
  • Further guidance for milk and egg allergy are given as these are relatively common food allergies with distinctive natural histories



Take an allergy-focused history. Please include the following information below in your referral (the EATERS mnemonic is useful(1) ):

Exposure by consumption of, or sometimes contact with, allergen

Allergen - Which food(s) ingested, and how much of that food caused the reaction? Is it a common allergen?

Timing from exposure to symptoms (most IgE mediated reactions occur within 1 hour and reactions after 2 hours extremely unlikely to be IgE mediated)

Environment - where did reaction occur

Reproducible – has child had that food since with no reaction? If so, they are not allergic to that food

Symptoms and signs in relation to the food exposure – always note severity, particularly where airway or circulation involved (anaphylaxis). Often a dose- response relationship but can be unpredictable. Subsequent reactions not always worse (good to reassure patients of this).


Please also include in your history:

  • Feeding history in infants, including whether breast or formula fed / weaning and any timings of feed changes vs symptoms
  • Allergic co-morbidities (esp. asthma, eczema, rhinitis) present?
  • Family history of current / past atopy – NB.family history of food allergy alone is not an indication for referral but can increase anxiety around introducing new foods.
  • Whether alternative testing such as hair analysis, kinesiology, blood IgG or Vega testing have been sought. These are not recommended by the British Society for Allergy and Clinical Immunology (BSACI)


Based on history, decide which type of allergy you suspect – IgE – mediated or non-IgE mediated

IgE-mediated symptoms 
have acute onset (usually minutes, not more than 1-2 hours post exposure) and include one or a combination of urticaria, angioedema, rhino-conjunctivitis (rare on its own), wheeze, stridor, repetitive and copious vomiting, sleepiness, collapse

Any airway involvement or circulatory compromise = anaphylaxis even if no rash



  • Any child who has had a significant IgE-mediated reaction to a small amount of food,

(NB. Exception to this are acidic foods such as tomatoes, vinegar, citrus and pineapple which can make eczema and urticaria prone patients acutely flare. This is not usually a protein mediated allergy and referral is not needed).

  • Anaphylaxis to food


Non-IgE-mediated symptoms have delayed/non-acute onset and include exacerbation of atopic eczema, worsening of gastro – oesophageal reflux or reproducible abdominal upset (vomiting, loose stools) after that food and can often be managed in Primary Care.



  • For a diagnosis and treatment plan specific to non -IgE Cow’s Milk Allergy
  • Reassure parents that not a dangerous allergy
  • Try a trial of elimination of suspected allergen for 2-4 weeks. If child does not improve, allergy unlikely; treat for the reflux / constipation / eczema bearing in mind commonality of these conditions without food allergy being present
  • Re-introduce that food. If child does improve then worsens on re-introduction of food, make the diagnosis and advise avoidance. Paediatric dietitian referral may be considered if doubt about nutritional adequacies of diet or timings of food re-introduction


Refer Non-IgE allergy if:

  • Impacting on child’s diet – Refer to Dieticians in first instance
  • Child has faltering growth on serial weights (rare) due to non-IgE Allergy
  • Clinical suspicion of multiple food allergies after trial eliminations/re-introductions
  • Persisting parental suspicion of food allergy (especially in children or young people with difficult or perplexing symptoms), despite lack of supporting history.


Differential Diagnosis of Food Allergy:

IgE – mediated

  • Chronic spontaneous urticaria – itchy urticarial rash, not always related to food, but acidic foods can also flare this condition if it is pre-existing. Some 10-40% have angioedema too. See Urticaria and Angioedema


Non IgE – mediated

The conditions below are common, and can easily occur without non-IgE food allergy being present.

  • Gastro-oesphageal reflux
  • Constipation (Idiopathic)
  • Chronic diarrhoea (consider Toddler Diarrhoea)
  • Lactose intolerance 
  • Eczema (many reasons for flare-ups)
  • Rhinitis (usually aero-allergens)




1.Fifteen-minute consultation: The EATERS method for the diagnosis of food allergies. Mich Erlewyn-Lajeunesse at al, Arch Dis Child Educ Pract Ed 2019 Dec;104(6):286-291

Simon Bedwani, Consultant Paediatrician, Royal Cornwall Hospital,

                        Dr S Burns GP RMS

Date                            January 2022

Review Date               January 2023


Version No. 2.2