Nut Allergy
Information for patients and their families
Background
The number of people with a nut allergy is
increasing. Recent data suggest that up to 1 in 50
school entry children in the UK may be affected
with peanut allergy. Allergy to other nuts is less
common. This means that in most schools there
will be at least one child with a nut allergy and they
are now the most common cause of severe allergic
reactions to foods. A range of allergic reactions can
occur, from an itchy rash (urticaria) to anaphylaxis,
which in some cases can be fatal. Unlike some
other food allergies seen in childhood, nut allergy
continues to be a problem into adult life in up to
85% of cases. In other words, in the majority of
cases children do not ‘grow out of it’. Adults too
can present with nut allergy.
What causes nut allergy?
Allergies are a result of a hypersensitive immune
system which reacts to harmless proteins, like the
proteins found in nuts. The immune response
occurs in 2 phases. The first phase is known as
‘sensitisation’. This is when the immune cells
meet the nut protein for the first time, and responds
by producing an antibody (IgE) to the protein. The
patient does not experience any symptoms of an
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allergic reaction at this time. However, the next
time that individual has contact with the nut protein,
it is recognised by the immune system. The IgE
binds to the protein, triggering a release of various
chemicals, such as histamine. These chemicals
act on cells within the body to produce the
symptoms of allergy; skin rash, swelling and
wheezing. This phase is known as the ‘reaction’
phase.
Allergic disease tends to run within families, and
these patients are said to have ‘a genetic
susceptibility’. However, this genetic effect is not
predictable and an allergy can develop in someone
who does not have a family history of allergy, and it
can develop at any age.
How can nut allergy affect you or your child?
People who are allergic to nuts will usually have
reactions soon after being ‘exposed’ to nuts. In the
majority of cases this is within minutes, but
reactions can occur over a period of hours after
exposure. ‘Exposure’ can mean eating even a tiny
amount of nut, or in very sensitive individuals
touching nuts. Reactions vary from person to
person and on the degree of ‘exposure’.
Mild reactions:
Swelling around the mouth is a common symptom
of nut allergy. The medical name for this swelling is
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angioedema. Swelling of the lips or eyes can be
uncomfortable but is generally not dangerous.
Swelling can be dangerous if it causes difficulty in
breathing or swallowing.
An itchy rash which looks like a nettle sting or hives
may occur. The medical name for this rash is
urticaria. Urticaria is irritating but not dangerous.
Some patients will feel nauseous, may vomit or
have stomach cramps.
Severe reactions (anaphylaxis):
These are less common, but can be fatal. They
need urgent treatment.
1. If swelling (angioedema) occurs inside the
throat, it may cause difficulty in breathing.
People describe this as a feeling of
‘tightness in the throat’ and their voice may
become ‘croaky’.
2. There may be a sudden severe asthma
attack (wheezing in the chest, difficulty in
breathing).
3. Collapse and loss of consciousness.
Risk of severe reactions
Patients who are atopic (asthma, rhinitis, eczema),
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and nut allergic appear to suffer more from severe
reactions with breathing difficulty or collapse/loss of
consciousness. A major factor in preventing severe
attacks appears to be having good long-term
asthma control. It is therefore very important that all
patients have their asthma properly assessed and
regularly monitored.
Factors associated with severe reactions
1. Asthma that is poorly controlled, or a current
exacerbation of asthma
2. Adolescent age
3. Alcohol consumption
Treating allergic reactions;
Antihistamines
Antihistamines should reduce the severity of a
reaction because they block the effect of histamine,
which is released in allergic reactions. An
antihistamine is often all that is required to treat
milder reactions, such as urticaria (skin rash), or
angioedema (swelling), that isn’t affecting breathing
or swallowing. Modern antihistamines are unlikely
to cause sleepiness in the majority of individuals.
As well as the official name, each antihistamine will
have a trade name.
Official name:
Acrivastine
Trade name
Benadryl allergy relief
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Cetirizine
Chlorphenamine
Fexofenadine
Levocetirizine
Loratadine
Benadryl allergy; oral
syrup for children
Benadryl one a day
relief
Piriteze
Zyrtec
Piriton
Telfast
Xyzal
Clarityn
Chlorphenamine is an older antihistamine, often
prescribed to be used in the event of a reaction. It
is likely to cause sleepiness.
Remember!:
Taking an antihistamine does not mean that you
can eat nuts safely.
Adrenaline (also called epinephrine)
Adrenaline (epinephrine) treatment is required in
severe reactions. Adrenaline (epinephrine) is
prescribed by your GP or allergy specialist in the
form of a ‘pen’ device. Various pen devices are
available; Epipen, Anapen and Jext. All devices
come in an adult and a junior dose, and you or your
child will be prescribed the appropriate one
(according to the weight of your child). It is given
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as an injection into the outer aspect of the thigh,
and your doctor or nurse will show you how to do
this at the time of prescription. A partner or other
family member should also know how to use the
pen. Every adult who is responsible for caring for a
child who has been prescribed an adrenaline
(epinephrine) pen should know how to use it.
Various websites have useful information on the
use of the pen (www.epipen.co.uk,
www.anapen.co.uk), and it is a good idea to update
yourself and family members on a regular basis.
Trainer pens are available from the websites.
When should you inject adrenaline
(epinephrine)?
Knowing when to inject adrenaline (epinephrine) is
not always easy. How do you know that a reaction
has become bad enough to be dangerous? Here
are some guidelines:
A reaction is dangerous if:
You are feeling very short of breath with wheeze, or
‘tightness’ in the chest.
There is a lot of swelling which is affecting your
breathing or swallowing.
You feel faint or seem to be in danger of becoming
unconscious.
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The reaction is progressing much faster than any
reaction you have had before with significant
swelling, asthma type symptoms, or stomach pains.
Collapse, loss of consciousness.
A reaction is not dangerous if:
You have swelling on one or two parts of your
body, for example, your lip and eyelids, without any
difficulty in breathing or swallowing, and the
reaction is not getting worse.
You have a ‘nettle-rash’ with no other symptoms.
The reaction is not affecting your breathing and is
similar to previous reactions you have had which
settled with antihistamimes
The Golden Rule:
If in doubt, you should inject adrenaline
(epinephrine) and seek medical attention.
Adrenaline (epinephrine) can be given as well as
antihistamines.
For most people it is better to inject adrenaline
(epinephrine) when it was perhaps not essential
than to leave treatment until a reaction is life
threatening.
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Two adrenaline (epinephrine) pens should be
carried at all times. The dose can be repeated
after 10 minutes if there is no, or only partial
response to the first dose. If adrenaline
(epinephrine) is required, you must seek medical
help immediately.
For most people, injection of adrenaline
(epinephrine) is not dangerous. If you have high
blood pressure or heart disease then you should
talk to your doctor about the potential risks and
benefits of using an adrenaline (epinephrine) pen.
Medicines which may affect adrenaline
(epinephrine)
Beta- blockers
These are medicines which are used to treat high
blood pressure, heart disease, migraine, and
anxiety. Beta blockers are occasionally prescribed
to children. They work by blocking the effect of
adrenaline (epinephrine) - both the adrenaline
(epinephrine) produced by your own body and that
given by injection. Patients on Beta blockers may
not respond to adrenaline (epinephrine), or only
have a partial response. If they are required for
other medical conditions, your doctor will discuss
the benefits and potential risks and make a
decision on the best treatment for you.
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Monoamine oxidase inhibitor (MAOI) or tricyclic
antidepressants may interact with adrenaline
(epinephrine), and again the benefits and potential
risks should be discussed between you and your
doctor.
Antihistamines and adrenaline (epinephrine)
should be carried at all times.
Avoiding peanuts
Avoiding nuts is essential for all patients with a nut
allergy. Avoiding nuts can be difficult and the
following sections are intended to give helpful
advice, but cannot include all situations in which
you or your child may be at a risk of exposure to
nuts.
At home
The best safeguard is to have no foods containing
nuts in the house - ‘a nut-free zone’.
Food labelling
Avoiding foods which are known to contain nuts
should be easy e.g. Snickers bars, salted peanuts,
dry roast peanuts, peanut butter, crunchy nut
cornflakes, nutella, fruit and nut cereal.
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Other names for peanuts include monkey nuts,
arachis nuts, or ground nuts.
Nuts may however be ‘hidden’ in other foods: raw
peanuts may be sold mixed with raisins or other
dried fruit in muesli. They may be found in nougat,
nut toffee and various other snack bars and
biscuits. Raw peanuts are also in some bird and
pet foods.
Within the UK and European union, all pre-packed
foods, including alcoholic drinks must show clearly
on the label if it contains peanut or tree nuts.
Some foods are guaranteed to be free from nuts.
Look for ‘This food does not contain nuts’, ‘Nut
free’, or ‘Suitable for nut allergy sufferers’. Some
products may carry labelling such as ‘May contain
traces of nuts’, or ‘Made in a factory where nuts are
packaged’, highlighting the possibility of accidental
contamination. It is difficult to gauge the level of
risk from these statements, and you should either
avoid foods with this labelling, or contact the
manufacturer for more information. You should
check the list of ingredients as well as the allergy
advice.
On occasions, a food has to be withdrawn from
sale because of a food allergy risk (missing or
incorrect labelling, or new allergy risk). You can
sign up for a free SMS text message or e mail
service to alert you to this at:
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www.food.gov.uk/safereating/allergyintol/alerts
Eating out
When eating away from home, it is more difficult to
ensure that food is nut free, but there are things
you can do to reduce the chances of having a
problem.
Some restaurants provide food that is guaranteed
‘nut free’. If you phone in advance, advising of your
nut allergy, the chef may be able to prepare a ‘nut
free’ dish. With other restaurants it is important
that the waiter/ress is aware that you or your child
suffers from a nut allergy, and must avoid all nuts in
food. Contamination of a dish which does not
contain nuts is a potential problem and it may be
worthwhile discussing this with the waiting staff or
chef.
Peanuts are used extensively in cooking and may
not be obvious, especially in Malaysian, Chinese
and Indian dishes. Meals are not always made the
same way - so just because you have eaten a
particular dish before does not mean it will be safe
next time.
Others
Sometimes with events such as parties, eating out
and visiting friends it can be difficult to ensure that
food has not been contaminated with nuts.
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Antihistamines can be taken before events,
however this is not a substitute for checking the
contents of food, or asking how food has been
prepared.
At school
Currently, there is no policy that schools should ban
nuts. However, most schools will have a ‘nut free’
policy. If your child is diagnosed with a nut allergy,
you need to discuss this with the responsible
school teacher, so that in conjunction with the
school doctor, a care plan can be established for
your child. This care plan should clearly indicate
what allergies the child has, what their symptoms
might be should they be accidentally exposed, and
what to do in the event of a reaction occurring at
school. Medication that has been prescribed should
be stated, and a decision made as to the best
holding place for the medication; either with the
school nurse, teacher, or with the child him/herself
(older children).
Travelling
Peanuts are often handed out to passengers on
planes. If you know you get allergic symptoms
when you are near other people eating nuts, call
the airline and advise them that you have a nut
allergy, and could they avoid serving nuts on the
flight. Many airlines will also make an
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announcement, just after boarding, asking other
passengers to refrain from eating nuts during the
flight. The airline should be contacted well in
advance. They are under no obligation and it is
wise to check with them before you book your
flights. You should request written confirmation of
the agreement.
Some simple advice:
1. Know the word used for peanuts/nuts in the
local language (translation cards are available
from www.allergyuk.org/auk_transcards.aspx)
2. Take a typed note about your allergy (in the
local language, if possible). This will help you
avoid nuts and get treatment quickly if you
need it.
3. Ensure you have adequate supplies of
antihistamines and adrenaline (epinephrine),
plus asthma medication if required, which is
well in date for your trip. Ensure adrenaline
(epinephrine) pens are not stored above the
recommended temperature.
4. Ask your doctor for a letter stating that you
have an allergy and your medication will have
to be carried on board. Sharp objects,
including adrenaline (epinephrine) pens are not
allowed on board without a medical letter.
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What about other foods?
Other nuts?
Peanuts are not directly related to ‘tree nuts’ such
as brazil nuts, hazelnuts, walnuts or almonds,
however up to 50% of patients with a peanut allergy
will react to at least one type of tree nut. In
contrast some other patients with a peanut allergy
can eat tree nuts without reactions.
We advise patients who are allergic to any type of
nut that they should avoid all nuts. This is in case
you may be allergic to more than one type of nut, or
because peanuts may be ‘hidden’ with other nuts in
prepared food.
Legumes?
Peanut is a legume. Other legumes include peas,
chickpea, beans, soy, lentils and lupine. The
majority of patients with a peanut allergy do not
have an allergy to other legumes. The risk may be
greater with lupine, found in some flours and
pastas. If there is a history of a reaction to more
than one legume, be cautious when trying any of
the others.
What about peanut oil, or other nut/legume oil?
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Nuts are made up of many different proteins and it
is these proteins that are responsible for triggering
an allergic reaction. During manufacturing, some
oils go through a refinement process which
destroys or removes the majority of the protein
content of the oil. Therefore, many individuals who
have a peanut allergy will not react to refined
peanut oil. Most vegetable oils sold in large
supermarkets are refined. There are some
unrefined oils; ‘cold pressed’ or ‘gourmet’ oils, or
oils that peanut has been added for flavour. These
do have higher protein content, and may cause
allergic reactions in some peanut allergic
individuals.
What about cosmetics/moisturisers/other
medications?
Peanut oil is used in some products for treating dry
skin conditions, such as moisturisers or bath oils. It
may also be used in some cosmetic products, or
medications. There is limited evidence that these
products can cause allergic reactions in peanut
allergic individuals, although some reports of this
have been described.
What are the risks for brothers and sisters?
Parents with one child who have a nut allergy are
naturally concerned about the risks for their other
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children. Current estimates suggest that brothers
and sisters of peanut allergic children are about 10
times more likely to have a peanut allergy than
other children. This means that approximately 1 in
5 of them will be peanut allergic.
If you have a nut allergic child, your house should
be a ‘nut-free zone’ and therefore brothers and
sisters should not be exposed to nuts at home.
Testing of brothers and sisters is possible, but
allergy tests have limitations, and can only give a
likelihood of an allergic reaction in an individual
who has never been exposed.
Can peanut allergy or other nut allergy be
prevented?
There is no evidence that avoiding peanuts in
pregnancy/breast feeding reduces the risk to the
child.
In 1998 the UK government’s Chief Medical
Officer’s Committee published a report on peanut
allergy recommending that pregnant women who
had a history of atopy (asthma, eczema, hay fever
or food allergy), or if the father or any sibling of the
unborn child had atopic disease, the mother should
avoid peanut and peanut containing foods during
pregnancy and breast feeding. The child should
avoid peanut containing foods until they were at
least 3 years of age.
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In light of new evidence, the 1998 advice was
changed. In August 2009 the Department of Health
and the Food Standards Agency issued new advice
stating that mothers may eat peanuts during
pregnancy or breast feeding, if they wish to do so.
Peanuts should not be introduced into a child’s diet
before 6 months.
Putting the risk in perspective
Nut allergy can be life threatening in a small
minority of patients. The majority of patients with
nut allergy never have a dangerous reaction.
Around 6 deaths from anaphylaxis to food occur
each year in the UK, a relatively low risk in
comparison to deaths from other causes such as
accidents or asthma. It is important to keep things
in perspective and with sensible precautions you
(or your child with nut allergy) should be, and feel,
very safe.
A Final Note:
This leaflet has been extensively revised by Dr Lisa
Devlin, Specialist Registrar in immunology. It
incorporates information from a number of sources,
which is for your interest but is not a substitute for
individual medical advice given to you or your child
by an appropriately qualified health professional.
The advice in this leaflet should not be used if it
conflicts with advice you have been given by such
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a person. We take no responsibility for following the
advice given in this leaflet. If you feel there are
issues raised that may affect you – you should
discuss these with your doctor(s).
Ideas for improvements to this leaflet should be
sent to:
Dr JDM Edgar
Consultant Immunologist
The Regional Immunology Service, Belfast
Health and Social Care Trust
Royal Hospitals
Grosvenor Road
Belfast BT12 6BA
For further information
The Anaphylaxis Campaign is a self-help
association for people in danger of anaphylaxis or
with a child in danger from it.
They may be contacted at:
Anaphylaxis Campaign
PO Box 275
Farnborough
Hampshire
GU52 6SX
e-mail: info@anaphylaxis.org.uk
www.anaphylaxis.org.uk
Allergy NI
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Co-ordinator:
Maureen Paul
www.allergyni.co.uk
E-mail: info@allergyni.co.uk
Tel : 02894433062
Other web sites:
www.peanutallergy.com
www.allergyuk.org
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