Anaphylaxis
Anaphylaxis
About anaphylaxis
Anaphylaxis is a severe allergic reaction and requires
immediate medical attention
. Within minutes of exposure to the allergen, or ‘trigger’, a person can have potentially life-threatening symptoms such as breathing and/or heart symptoms.
There is currently no cure for
allergy
.
The best way to prevent anaphylaxis is to avoid whatever causes the allergic reaction. When accidental exposure occurs follow instructions on your
Australasian Society of Clinical Immunology and Allergy Action Plan for Anaphylaxis (ASCIA Action
Plan)
External Link
.
People at risk of anaphylaxis must always carry their ASCIA Action Plan and their adrenaline injector (EpiPen® or Anapen®) with them at all times.
If you are thought to be at risk of anaphylaxis or you have anaphylaxis for the first time, your doctor will refer you to a clinical immunology/allergy specialist, who will make a diagnosis and provide advice on preventative management and emergency treatment.
Anaphylaxis is a severe allergic reaction
Allergy occurs when the
immune system
overreacts to a substance or ‘trigger’ in the environment that is harmless for most people. The trigger is called an allergen. The immune system responds by making an antibody to attack the allergen and this starts off a range of immune system reactions.
Allergies can be mild, moderate or severe.
Anaphylaxis is the most severe type of allergic reaction. Hospital admissions for anaphylaxis have increased five-fold in the last 20 years and anaphylaxis from food allergy reactions has doubled in the last 10 years.
Signs and symptoms of anaphylaxis
Anaphylaxis can occur within minutes. It mostly occurs within 20 minutes to 2 hours after exposure to the allergen.
Signs and symptoms may be mild at first, but can get worse very quickly. A small number of people suddenly develop signs and symptoms of a severe allergic reaction (anaphylaxis) without any signs of a mild to moderate allergic reaction.
Signs of a mild to moderate allergic reaction include:
swelling of lips, face, eyes
hives
or welts appearing on the skin
tingling mouth
abdominal pain, vomiting (these are signs of anaphylaxis for insect allergy).
Signs of a severe reaction (anaphylaxis) include:
difficult/noisy breathing
swelling of tongue
swelling/tightness in the throat
difficulty talking and/or hoarse voice
wheeze or persistent cough
persistent dizziness or collapse
pale and floppy (in young children).
Triggers for anaphylaxis
Some of the more common triggers (allergens) that can lead to anaphylaxis include:
food
– any food can be a trigger. However, the foods that account for about 90% of allergic reactions are
shellfish
,
fish
,
eggs
,
milk
, wheat,
peanuts, tree nuts, sesame
and
soy
insect bites and stings
– including bees, wasps, jack jumper ants, green ants and fire ants. Ticks (arachnids) can also trigger anaphylaxis
medicines
– some prescription drugs (such as penicillin), over-the-counter medicines (such as aspirin) and herbal preparations.
Less common triggers include exercise, anaesthetic drugs and
latex
.
Sometimes, despite many investigations, a person’s trigger allergen/s cannot be identified. These are referred to as ‘unknown triggers’.
Risk factors for anaphylaxis
There are a number of factors that appear to increase the risk and/or severity of anaphylaxis at the time of exposure to the allergen/trigger. These include:
poorly controlled
asthma
exercise
alcohol
fatigue (tiredness)
posture
– standing and walking
hormonal changes (for example, in women that are
premenstrual or menstrual
)
amount of food eaten and how it is prepared (in people with food allergy)
taking a non-steroidal anti-inflammatory medication such as aspirin or ibuprofen.
Diagnosis of allergy
If you are thought to have a moderate/severe allergy or you experience anaphylaxis for the first time, your general practitioner (GP) will:
record the history of your allergic reaction and suspected trigger/s
refer you to a clinical immunology/allergy specialist
inform you about patient support services, such as
Allergy & Anaphylaxis
Australia
External Link
.
A GP cannot provide an individual with an initial
authority prescription for an adrenaline injector (EpiPen® or
Anapen®
External Link
) unless this is done in consultation with a clinical allergy/immunology specialist.
In order to make a diagnosis, the clinical immunology/allergy specialist will:
Take a medical history including detailed questioning about what led up to the event.
Perform a physical examination.
Perform investigations. These could be:
blood tests to measure allergen specific antibodies, known as immunoglobulin E (IgE)
skin prick tests
to confirm or rule out suspected triggers
tests to exclude other medical conditions that can look like an allergic reaction or anaphylaxis.
Some ‘allergy tests’ are not proven
Some ‘tests’ that claim to diagnose allergies are not scientifically or medically proven.
Tests that are not proven to provide accurate information on your trigger/s for allergic reactions, including anaphylaxis, can be dangerous. Relying on an unproven test may mean you don’t get the medical attention you need. It may also delay you receiving a diagnosis and anaphylaxis management advice. It can be expensive and also result in unnecessary dietary and lifestyle restrictions.
Some alternative testing methods that may lead to inappropriate or inadequate treatment include:
Alcat testing
allergen elimination techniques
cytotoxic food testing
kinesiology
hair or stool analysis
IgG antibody testing to food
iridology
pulse testing
reflexology
Rinkel’s intradermal testing
Vega testing.
Management of allergy
Your clinical immunology/allergy specialist will discuss:
how to prevent an allergic reaction. For food allergy, advice from an experienced food allergy dietitian may also be needed
how to manage an allergic reaction. This includes completing an ASCIA Action Plan for Anaphylaxis/Allergic reactions that outlines emergency management and providing education on how to use an adrenaline injector if prescribed.
Your clinical immunology/allergy specialist may prescribe an adrenaline injector). Not everyone with a food, insect or other allergy will be prescribed an adrenaline injector. The specialist will assess level of risk. Those with medication allergy are generally not prescribed an adrenaline injector as the trigger is easier to avoid compared to food or insect allergy.
You will need regular follow-up visits with a clinical immunology/allergy specialist.
Treatment for anaphylaxis
Anaphylaxis is a medical emergency.
Emergency treatment includes following instructions on your individual ASCIA Action Plan for Anaphylaxis or
First Aid Plan for
Anaphylaxis
External Link
.
Lay the person flat (do not allow them to stand or walk).
Give adrenaline injector.
Phone ambulance – dial triple zero (000).
Phone family/emergency contact.
Further adrenaline doses may be given if no response after 5 minutes.
Transfer person to hospital for at least 4 hours of observation.
Always give adrenaline injector
first
, and then asthma reliever puffer if someone with known asthma and severe allergy to food, insect or medication has
sudden breathing difficulty
, even if no skin signs (hives or welts) are present.
Commence
CPR
at any time if the person is unresponsive and not breathing normally.
Adrenaline injectors
Adrenaline is the first line treatment for anaphylaxis. Adrenaline is injected into the muscle of the outer mid-thigh (that is, midway between the knee and hip joints on the outer side of the thigh) using an adrenaline injector.
Once you are diagnosed at risk of anaphylaxis, it is important to always carry your adrenaline injector/s and your ASCIA Action Plan, which is completed and signed by your doctor or nurse practitioner.
In Australia, the devices currently available are EpiPen® and Anapen®. They are prescribed on an ‘authority prescription’, allowing people to get 2 government-subsidised devices (on the
Pharmaceutical Benefits Scheme (PBS)
). They are also available over the counter at the pharmacy at full cost.
The adrenaline injectors are designed to deliver a single pre-measured dose of adrenaline.
EpiPen® comes in 2 doses:
EpiPen® for children over 20kg and adults
EpiPen® Jnr for children who weigh between 7.5kg and 20kg.
Anapen® comes in 3 doses:
Anapen® 500 for children and adults over 50kg
Anapen® 300 for children over 20kg and adults
Anapen® 150(Jr) for children who weigh between 7.5kg and 20kg.
You will be given detailed instructions on how to use your adrenaline injector from your treating doctor or pharmacist. ASCIA has information on
adrenaline injectors and frequently asked
questions
External Link
.
You can also
visit Allergy & Anaphylaxis
Australia
External Link
to view videos on signs and symptoms, how to position a child/adult during anaphylaxis and how to use an EpiPen® and Anapen®.
Prevention of anaphylaxis
The best way to avoid anaphylaxis is to:
avoid triggers – the most important management strategy is to avoid all known triggers (allergens)
if you have a
food
allergy
External Link
, always read food labels and tell staff about your allergy when eating out
if you have an
insect
allergy
External Link
, always be aware of environments that may increase the risk of insect sting or bite, and do what you can to minimise exposure.
Other recommendations include:
Complete the free, online
ASCIA Anaphylaxis e-training for first aid
(community)
External Link
.
Tell people about your allergy:
Let your workplace know about your allergy, and make a few work colleagues aware of where your emergency medication is kept, and how to administer it to you.
If you have a medication allergy, be sure to always tell every treating doctor and pharmacist about your allergy.
Wear a medical identification bracelet – if you lose consciousness, your medical identification bracelet will alert ambulance officers or hospital staff of your condition.
If you are finding your food allergy difficult to manage, or if you have multiple food allergies, consider making an appointment with a specialised food allergy dietitian.
Take extra precautions when eating out if you have a food allergy.
Take extra precautions when travelling with allergy.
Seek information and support from
Allergy & Anaphylaxis
Australia
External Link
- an evidence-based organisation with information, resources and support from trained allergy educators.
Children with severe allergies
Suggestions for parents of children with severe allergies include:
Educate your child, taking their age and level of understanding into account. If your child has food allergy, stress the importance of only accepting food from trusted adults such as parents or caregivers, never sharing food and washing hands before and after eating.
Advise the childcare service, kindergarten, school and other carers of your child’s severe allergy.
Give the organisation a current copy of your child’s ASCIA Action Plan, which includes a recent photograph of your child.
Make sure you provide at least one in-date adrenaline injector.
Work with your child’s
school
External Link
or
childcare
External Link
setting to implement a management plan to reduce the risk of allergic reactions, including anaphylaxis. Allergy Aware’s Best Practice Guidelines and resources have been developed to guide schools and early children’s education and care services on anaphylaxis prevention and management.
Long-term outlook for allergy
Most children grow out of allergies to milk, egg, wheat and soy. However, allergies to peanut, tree nuts, sesame and seafood are usually lifelong.
People that have had anaphylaxis because of insect allergy should discuss with their clinical immunology/allergy specialist if immunotherapy (desensitisation) is available and suitable for them.
Anaphylaxis training
Anaphylaxis training options include:
ASCIA Anaphylaxis e-training for first aid
(community)
External Link
– this is online training for members of the community, such as parents, friends, carers, workplace colleagues, students and club members.
ASCIA Anaphylaxis e-training for schools and children’s
education/care
External Link
.
Food allergy
training
External Link
– free, online food allergen management training developed by the National Allergy Council (NAC) that includes courses for food business staff, cooks and chefs, schools, children’s education and care, camps, hospitals and residential care.
Where to get help
In an emergency, always call triple zero (000)
Your
GP (doctor)
Allergy & Anaphylaxis Australia
(A&AA)
External Link
Tel.
1300 728 000
Anaphylaxis Support Advisory
Line
External Link
(Royal Children’s Hospital Melbourne) Tel.
1300 725 911
Australasian Society of Clinical Immunology and Allergy
(ASCIA)
External Link
Dietitians
Australia
External Link
Tel.
1800 812 942