Menu Search Donate
clinical guideline banner

Allergy myths

This document is only valid for the day on which it is accessed. Please read our disclaimer.

Allergic reactions get worse with each exposure

This is often a concern for parents but the scientific studies into this process show that it is untrue. There is as much chance of a less severe reaction on subsequent exposure as there is of more severe. The actual rate of fatal food reaction in children is extremely low; estimated at 1.8 per million person years living with food allergy. This is slightly more likely than dying from being struck by lightning.

Artificial E-numbers and preservatives can cause allergic reactions

E-numbers are food additives which can be synthetic or natural. Some are essential vitamins, such as vitamin C and B2 (E300 and E101 respectively). The vast majority of allergies are to food proteins. True reactions to food additives are rare and generally to E-numbers that have a natural origin, eg. Annatto (E160b) - natural colour extracted from a seed. 

Food allergic people can react without ingestion

For the majority of food allergic individuals the protein responsible for the allergy must be ingested to cause symptoms. Being near a food, such as peanut, will not cause an allergic reaction in almost all peanut allergic people. There are a few exceptions, such as steaming fish or boiling milk. This can release small amounts of protein into the surrounding area which can affect people who react at very low doses of the food.

Avoiding highly allergenic foods in infancy / breastfeeding prevents allergy

In 2008, the American Academy of Pediatrics recommended early childhood avoidance of highly allergenic foods (milk, egg, peanut) to prevent allergy. We now know this is unhelpful and in fact may increase the risk of allergy. In 2015, the LEAP study was published1 demonstrating early exposure (from 4 months) to peanut in high risk infants and then continuation through childhood reduced the risk of peanut allergy by as much as 7-fold. Similar results have been found with egg and milk. There is no evidence to support maternal dietary restriction in pregnancy or breastfeeding to prevent or treat atopic dermatitis2.

Adjusting diet based on sensitisation can improve eczema control

There is no evidence that dietary modification is effective to manage mild infantile eczema. Some studies have suggested a role in moderate-severe eczema that is treatment resistant3. Egg is the most commonly considered culprit in this scenario. Testing for IgE to foods that are regularly ingested without IgE mediated reaction (hives, swelling, itch, breathing difficulty within 1-2hrs) can find many low level positive tests that are meaningless. Further, avoidance of these foods may allow loss of tolerance and development of allergy.

References

  1. Du Toit G, et al. N Engl J Med. 2015;372(9):803-13.
  2. Kramer MS, Kakuma R. Evid Based Child Health. 2014;9(2):447-83.
  3. Bath-Hextall F, Delamere FM, Williams HC. Allergy. 2009;64(2):258-64.

Did you find this information helpful?

Document Control

  • Date last published: 16 December 2015
  • Document type: Other
  • Services responsible: Paediatric Immunology
  • Owner: Kahn Preece
  • Editor: Greg Williams
  • Review frequency: 2 years

More From Starship