Food allergy and intolerance
Food allergy and intolerance
If you, or someone in your care, has a severe allergic reaction, call triple zero (000) for an ambulance. The person having the reaction should not stand or walk. Administer an adrenaline (epinephrine) injector (such as EpiPen® or Anapen®) into outer mid-thigh. Further doses of adrenaline may be given if no response after 5 minutes. Give adrenaline first, then asthma reliever puffer, if required.
Food allergy and intolerance are different
Food allergy and food intolerance are commonly confused, as symptoms of food intolerance occasionally resemble those of food allergy. However, food intolerance does not involve the
immune system
and does not cause
severe allergic reactions (known as anaphylaxis)
. Food intolerance also does not show on
allergy testing
, and the Australiasian Society of Clinical Immunology and Allergy (ASCIA)
advises against non evidence-based allergy
tests
External Link
.
Food intolerance can be a difficult concept to understand. Sometimes, substances within foods can increase the frequency and severity of
migraine headaches
, rashes (such as
hives
) or the stomach upset of
irritable bowel
.
For more information watch the animated video
How Allergies
Work
External Link
on the
ASCIA
website
External Link
.
Professional diagnosis of food allergy by a
clinical immunology/allergy
specialist
External Link
is important.
Food allergy is increasing
Allergies
are on the increase worldwide and
food allergies
have also become more common. Most allergies appear during the first year of life.
Cow’s milk allergy
is one of the most common in early childhood. Most children grow out of cow’s milk allergy before they start school.
More
research
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is needed into the causes, diagnosis and treatment of food allergy.
Allergy can be inherited
Children who have one family member with allergic diseases (including
asthma
or
eczema
have a higher risk of developing allergy.
Most of the time, children with food allergy do not have parents with food allergy. However, if a family has one child with food allergy, their brothers and sisters are at a slightly higher risk of having food allergy themselves, although that risk is still relatively low.
Allergy is an immune response
Allergies are an overreaction of the body’s immune system to a
protein
. These proteins may be from:
foods
pollens
house dust
animal dander (includes fur, wool and pollens brought into the home by pets)
moulds
.
They are called allergens. The word allergy means that the immune system has responded to a usually harmless substance as if it were toxic.
Food intolerance is a chemical reaction
Food intolerance is a chemical reaction that some people have after eating or drinking some foods; it is not an immune response. Food intolerance has been associated with asthma,
chronic fatigue syndrome
and irritable bowel syndrome (IBS).
Symptoms of food allergy and intolerance
It can be difficult to tell the difference between the symptoms of food allergy and food intolerance. Usually, symptoms caused by food allergy develop very soon after consuming the food. While symptoms caused by food intolerance can be immediate, they may also take 12 to 24 hours to develop.
Food intolerance reactions are usually related to the amount of the food consumed. They may not occur until a certain amount (threshold level) of the food is eaten, but this amount varies for each person.
The symptoms of food allergy and intolerance can also be caused by other conditions, so it is important to see your doctor for a medical diagnosis.
Symptoms of food intolerance
Symptoms of food intolerance can include:
nervousness
tremor
sweating
palpitations
rapid breathing
headache
, migraine
diarrhoea
burning sensations on the skin
tightness across the face and chest
breathing problems – asthma-like symptoms
allergy-like reactions.
Symptoms of food allergy
The symptoms of mild to moderate food allergy include:
swelling of lips, face, eyes
hives
or welts
tingling mouth
abdominal pain, vomiting – these are signs of
anaphylaxis
for insect allergy.
Signs of anaphylaxis (severe allergic reaction):
difficult or noisy breathing
swelling of tongue
swelling or tightness in throat
wheeze or persistent cough
difficulty talking or hoarse voice
persistent dizziness or collapse
pale and floppy (young children).
Action plans for anaphylaxis are available at
ASCIA Action, First Aid, Management, Travel and Treatment Plans and
Guides
External Link
.
Body parts affected by food allergy
Various sites on the body can be affected by an allergic reaction to food, including:
swelling of the face, lips, eyes
swelling of the tongue
swelling or tightness in the throat
stomach pains, vomiting – these are signs of anaphylaxis for insect allergy
skin – rashes, such as hives (urticaria) or atopic dermatitis
lungs – wheeze, cough, asthma (more common in children than adults).
Severe allergic reactions to foods can be life-threatening
Anaphylaxis
is a severe allergic reaction that needs urgent medical attention. Foods (such as
peanuts, tree nuts
,
seafood
, wheat,
milk
and
eggs
),
insect bites and stings
and some
medicines
are the most common allergens that cause anaphylaxis.
Within minutes of exposure to the allergen, the person can have potentially life-threatening symptoms, which may include:
difficult or noisy breathing
swelling of tongue
swelling or tightness in throat
wheeze or persistent cough
difficulty talking or hoarse voice
persistent dizziness or collapse
pale and floppy (young children).
Several factors can influence the severity of anaphylaxis, including exercise, heat, alcohol, the amount of food eaten, and how food is prepared and consumed.
Emergency treatment for severe allergic reactions (anaphylaxis)
To
prevent severe injury or death
, a person with anaphylaxis requires an injection of
adrenaline
External Link
(epinephrine) into the outer mid-thigh. They should not be allowed to stand or walk. Further doses may be given if there is no response after 5 minutes. Give adrenaline first, then asthma reliever puffer, if required.
People who are considered by their doctor to be at risk of anaphylaxis are prescribed an adrenaline injector (such as an EpiPen® or Anapen®), which contains a single fixed dose of adrenaline. These patients should also have an
ASCIA Anaphylaxis Action
Plan
External Link
.
Adrenaline injectors are designed to be used by non-medical people, and are available directly from a pharmacy.
Causes of food allergy
Peanuts, tree nuts, eggs, cow’s milk, wheat, sesame, fish, shellfish and soy cause the majority of food allergic reactions. Peanut allergy is one of the most common allergies in older children as only approximately one in 4 children will outgrow peanut allergy.
Causes of food intolerance
The foods that tend to cause intolerance reactions in sensitive people include:
dairy products, including milk, cheese and yoghurt
chocolate
eggs, particularly egg white
flavour enhancers such as MSG (monosodium glutamate 621)
food additives
strawberries, citrus fruits and tomatoes
wine, particularly red wine
histamine and other amines in some foods.
Finding the allergen
When symptoms appear within a few minutes of eating the particular food, it makes pinpointing the allergen an easy task. However, if the cause is unknown, diagnostic tests may be needed, such as:
keeping a food and symptoms diary to check for patterns
under the supervision of a
clinical immunology/allergy
specialist
External Link
or dietitian, removing all suspect foods for 2 weeks, then reintroducing them one at a time to test for reactions (except in cases of anaphylaxis)
skin prick tests using food extracts or IgG blood tests.
ASCIA strongly recommends only having
evidence-based
External Link
allergy tests.
Treating food allergy or intolerance
The easiest way to treat a food allergy or intolerance is to eliminate the offending food/s from the diet. Sometimes, the body can tolerate the food if it is avoided for a time, then reintroduced in small doses, particularly for food intolerances.
Before you eliminate or reintroduce foods, seek advice from a
clinical immunology/allergy specialist or
dietitian
External Link
.
Preventing food allergy in children
Allergy prevention in children is an active area of research. Findings to date indicate that:
Prenatal – there is no conclusive evidence that avoiding allergens in
pregnancy
will help prevent allergies in your child.
Postnatal – exclusive
breastfeeding
during the first 4 to 6 months appears to protect against the development of allergies in early childhood.
Introducing solid
foods
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(including those considered to be allergenic) around 6 months (but not before 4 months) is recommended, preferably while continuing to breastfeed.
Breastfeeding – avoidance of a food (including foods considered to be highly allergenic) by a woman while breastfeeding is not recommended.
Soymilk formula – studies have shown that using soymilk formula does not prevent the development of allergies in children.
Partially hydrolysed cow’s milk-based formula (commonly referred to as HA formula) is not recommended to prevent the development of food allergy.
Severe food allergy in children
Allergic reactions, including anaphylaxis, are common, although deaths from anaphylaxis are rare. All
schools and childcare
services
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across Australia are required to have an anaphylaxis management policy in place. Teachers in every state are trained to recognise and react to an allergic reaction by completing ASCIA Anaphylaxis e-training. They should also practise using an adrenaline injector training device.
Banning particular foods in schools and early childcare is not recommended as it can create a sense of complacency and is difficult to monitor and enforce. A better approach is to educate staff, students and the community about the risks associated with anaphylaxis and put strategies in place to minimise exposure to known allergens. The
Allergy
Aware
External Link
website has many resources available.
Food allergen avoidance
You should only avoid foods to which you have a diagnosed allergy. Learn the terms used to describe these foods on food labels, for example:
milk protein – milk, non-fat milk solids, cheese, yoghurt, caseinates, whey, lactose
lactose – milk, lactose
egg – eggs, egg albumen, egg yolk, egg lecithin
gluten – wheat, barley, rye, triticale, wheat bran, malt, oats, cornflour, oat bran
soy – soybeans, hydrolysed vegetable protein, soy protein isolate, soy lecithin
salicylates
External Link
– strawberries, tomatoes.
The
National Allergy
Strategy
External Link
has developed a resource hub to assist with best practice procedures for food allergen management.
Food laws and labels
Since December 2002, the Australia New Zealand Food Standards Code requires food labels to declare certain foods and certain substances in foods, including:
cereals that contain gluten and gluten products
shellfish and their products
eggs and egg products
fish and fish products
milk and milk products
tree nuts, sesame seeds and their products
peanuts
soybeans and their products
added sulphites in concentrations of 10 mg/kg or more
royal jelly (presented as food or present in food), bee pollen and propolis.
These foods must be declared if they are:
used as an ingredient
part of a compound ingredient
a food additive or part of a food additive
a processing aid or part of a processing aid.
Where to get help
In an emergency, always call triple zero (000)
Emergency department of your nearest hospital
Your
GP (doctor)
NURSE-ON-CALL
Tel.
1300 606 024
(24 hours, 7 days) – for health information and advice
Australasian Society of Clinical Immunology and
Allergy
External Link
– Locate a specialist
Allergy & Anaphylaxis
Australia
External Link
Dietitians
Australia
External Link
Nutrition
Australia
External Link
Tel.
(03) 9650 5165