Anaphylaxis

What is anaphylaxis?

Anaphylaxis is a serious allergic reaction to a substance (inhaled, eaten or brushed against the skin) which can be life threatening. Anaphylaxis is also known as anaphylactic shock.

Anaphylaxis involves the release of the antibody IgE, which causes the release of high levels of histamine in response to ingestion, touch or inhalation of a certain substance to cause a inflammatory response in the body to the allergen, which the body views as toxic. If the release of histamine is not reduced, it can cause very serious symptoms that can ultimately be life threatening.

Anaphylaxis happens very quickly, sometimes without much warning (especially if the person does not realise they are allergic to a particular substance or if they eat something with a known allergen, but they are unaware of this). This condition can lead to death if not treated promptly and if the allergic reaction is serious and intense.

Facts about anaphylaxis

• A person with anaphylaxis needs immediate medical assistance
• People with known serious allergies to substances should wear identifying bracelet to alert people to their condition if they cannot talk during a serious anaphylaxis reaction
• An injection of adrenaline is the only way to prevent death from a serious anaphylaxis reaction
• Anaphylaxis can occur within seconds or minutes of exposure to an allergen
• Biphasic anaphylaxis symptoms (those symptoms which happen 2-3 hours after first, initially mild symptoms) occur in about 20% of all cases of anaphylaxis

Symptoms of anaphylaxis

Symptoms of anaphylactic shock tend to develop rapidly although the initial presentation can be delayed and/or deceptively mild.

General initial symptoms of anaphylaxis

These generally which occur within a few minutes to two hours after contact with the allergen are:

• Itching
• Metallic taste in the mouth
• Tingling sensation

Other symptoms of anaphylaxis

• Coughing
• Diarrhoea
• Hives
• Loss of consciousness
• Low blood pressure
• Sensation of warmth
• Stomach cramps
• Swelling of the mouth and throat area
• Vomiting
• Wheezing or other difficulty breathing

Symptoms sometime start quite mildly and can progressively get worse over a number of hours.

Biphasic anaphylaxis

In about 20% of all cases of anaphylaxis, symptoms start off quite mild, go away and then come back about 2-3 hours later with alarming severity. The second-phase symptoms occur in the respiratory tract and are usually more severe than the first-phase symptoms.

How anaphylaxis occurs

Anaphylaxis is most likely to happen if one of the following three scenarios occurs within minutes to an hour after eating a food allergen or being exposed to the allergen (insect bite etc) (adapted from Food Allergy and Anaphylaxis Network)

1. Skin symptoms or swollen lips

A person has an allergic reaction of the skin (hives, rash) or swollen lips and either the symptoms below:

• Difficulty breathing
• Lowered blood pressure

2. Exposed to a suspected allergen

If a person has been exposed to an allergen and two or more of the following symptoms also occur:

• Difficulty breathing
• Gastrointestinal symptoms (cramping pain, diarrhoea, vomiting)
• Lowered blood pressure
• Skin symptoms (rash, hives) or swollen lips

3. Exposed to a known allergen

If a person was exposed to a know allergen and experiences:

• Lowered blood pressure

Anaphylactic shock affects most body systems in a devastating way and can be fatal.

Causes of anaphylaxis

Anaphylaxis can be caused by a number of allergens, which trigger this serious and extreme reaction.

The most common causes of anaphylaxis are:

Foods

Certain foods are most common and major triggers of anaphylaxis (especially peanuts). Many more children these days have a serious reaction to peanuts, which can end up in a serious anaphylactic reaction.

Exercise

Surprisingly, exercise is a little known cause of anaphylaxis and that is most likely due to it triggering a severe asthma attack that develops in a serious anaphylactic reaction. This is a less common cause of anaphylaxis and usually only occurs when food is eaten and then exercises 3-4 hours after eating it.

Insect bites

Insect bites are another common cause of anaphylaxis. The site of the insect bite is the first point of swelling and symptoms often can get worse from there. The insects that most commonly cause anaphylaxis in people susceptible are: bees and wasps.

Latex

Contact with latex (which was originally made from the sap that comes from the rubber tree) is another common cause of anaphylaxis. People who are allergic to latex cannot allow it touch their skin, otherwise it could cause an anaphylactic reaction. Latex is most commonly found in balloons, condoms, food preparation gloves, rubber bands and some toys.

Medicines

An anaphylactic reaction, while rare, can occur when taking any type of medication in people who are allergic to that medication. Sometimes people do not know they have an allergy to a specific medication until they have anaphylaxis – although this is rare.

No underlying reason

Very rarely, anaphylaxis will occur with no underlying reason that can be found.

Prevention of anaphylaxis

Non-preventable risk factors

Anaphylaxis may be unpreventable in certain circumstances:

• Existing asthma – sometimes the asthma may be so severe that is causes an anaphylactic reaction, especially if the asthma is triggered by an allergen that is really severe. Studies also show that people who have both asthma as well as food allergies may be at increased risk for having a life-threatening anaphylactic reaction to the food (which is partly exacerbated by the asthma)
• Existing eczema – sometimes the eczema may be so severe that is causes an anaphylactic reaction, especially if the eczema is triggered by an allergen that is really severe
• Existing hay fever – sometimes the hay fever (allergic rhinitis) may be so severe that is causes an anaphylactic reaction, especially if the allergic rhinitis is triggered by an allergen that is really severe
• Genetics – families who have children that have anaphylaxis have a higher risk of those children producing their own children who also have anaphylaxis
• Unknown allergy – sometimes the first time a person (child usually) is aware they have a serious and life threatening allergy to a substance or food, is when they come into contact (eating, inhalation or touching) that substance and immediately develop a serious anaphylactic reaction. There is very little that can be done to prevent this since the allergy is unknown at the time, but much can be done prevent it from happening in future
• Unknown medicine allergy – sometimes the first time a person is aware they have a serious and life threatening allergy to a medicine, is when they develop a serious anaphylactic reaction to it after taking it. There is very little that can be done to prevent this as the allergy to the medication is then unknown, but much can be done prevent it from happening in future

People who have known and serious allergies should have an epipen on them at all times

Preventable risk factors

There are ways to prevent anaphylaxis from occurring in people with known and serious allergies to certain substances:

• Avoid allergen triggers – people (children especially) who know they are seriously allergic to a certain substance have to avoid any contact with it, to avoid a serious allergic reaction. Teachers at the school and other parents must be informed to reduce likelihood of the child unwittingly coming into contact with the allergen
• Avoid food triggers – people (children especially) who know they are seriously allergic to a certain food have to avoid not only that food, but any other processed food that may have had that ingredient added. This requires a lot of vigilance to prevent an allergic reaction. Teachers at the school and other parents must be informed to reduce likelihood of the child unwittingly coming into contact with the allergen
• Avoid latex gloves – this allergy is easier to avoid than some of the other ones, because latex is not often found in many places other than in latex gloves, balloons and some other items and can be easily avoided. A small amount of people though, are seriously allergic to latex and cannot even be in contact with anyone who has been wearing latex gloves
• Avoid medicines that cause an allergic reaction – medications that are known to cause a serious allergic reaction can be most easily avoided, but some vigilance is required, because the substance in those medicines can also be present in other medicines, which may sometimes not be easily identified
• Take care when exercising – people who know they can have a serious asthmatic reaction when they exercise need to ensure they are adequately prepared with their medication they take to prevent anaphylaxis
• Use insect repellant when outside – people with known serious allergic reactions to insect bites must wear some type of insect repellant and / or cover themselves to avoid being bitten by insects and prevent anaphylaxis

Complications of anaphylaxis

Anaphylaxis can be life-threatening if it is severe and needs urgent emergency medical treatment. Anaphylaxis can stop the heart or stop breathing, in which cause you will need CPR (cardio-pulmonary resuscitation) to get your heart beating again.

Emergency treatment of anaphylaxis usually involves administration of epinephrine (adrenaline). It will stop the allergic reaction and allow the body to react more normally again.

When to see a doctor about anaphylaxis

An unknown and severe allergy to a substance that causes anaphylaxis will require immediate and urgent medical treatment. Call an ambulance – 000.

People with known allergies who come into accidental contact with the allergen will need emergency medical treatment. If they are wearing their medical alert bracelet, it will give information about what they are allergic to and what treatment they need if they come into contact with the allergen. Call an ambulance – 000.

Diagnosis of anaphylaxis

Anaphylactic shock is mostly diagnosed during childhood, but can occur later in life too.

Sometimes the first time an allergy to a particular substance is known is when the child (or adult) has a serious allergic reaction to it which presents with the serious symptoms of anaphylaxis.

People with any type of allergies, asthma, eczema or allergic rhinitis, should see their doctor for confirmation of the condition. Initial diagnosis will include:

• Medical history – your doctor will take notes on the duration and severity of symptoms, when they started and will order other tests as necessary
• Physical examination – the doctor will perform a general physical examination of the throat, nose and ears to detect the severity of the condition

Diagnostic tests

The following tests will be requested to confirm diagnosis of allergy to a particular allergen:

• Allergy testing – an allergy test is usually a test which can give a clear understanding on which allergens are most likely to prompt symptoms in people with allergic rhinitis. An allergy tests is also known as a”skin prick test” and it involves pricking the forearm with a very small needle and allowing some of the allergen into the skin. This is done many times with various allergens that the allergy specialist uses (including dust and pet hair brought from home) to determine if an allergy exists to a particular substance. Usually, if an allergy to the substance occurs, it will cause the skin pricked to form a welt, rash or lump. The allergy specialist (or immunologist) will have taken note of each substance used to enable determination of the substances that cause the allergic response
• Cytotoxic allergy tests – this is a simple blood test which exposes the white blood cells to a sample of the suspected allergens (food or other substance) to determine if there is any reaction (the IgA antibodies in the white blood cells will react to the food or substance if it is an allergen that the body recognises). Sometimes this test can give false positives and may not be as reliable as an allergy test
• Food sensitivity test – children with allergies, asthma, eczema or hay fever often have food allergies or sensitivities and much of their subsequent symptoms may be due to this sensitivity. An elimination diet needs to be followed to work out if this food is causing any of the symptoms. The most common food sensitivities that can cause behavioural problems are: cow’s milk, wheat (or gluten), oranges (and other citrus fruit), chocolate, peanuts, soy, eggs, corn, oats, apples, tomatoes. In order to test a food sensitivity, that food (and foods containing it) must be totally eliminated from the diet for two weeks (as must all foods with any artificial additives) and after that, the food can be re-introduced back into the diet to see if there are any reactions to it. This requires a lot of vigilance and strict monitoring and could be better accomplished with the help of a registered dietician or naturopath

Conventional treatment of anaphylaxis

Conventional treatment of anaphylaxis consist of medication to stem the allergic reaction and advice on how to avoid the allergen in future:

Medications

• Adrenaline / epinephrine – should be administered to treat anaphylactic shock immediately. Adrenaline works to prevent the condition from progressing and quickly reverses symptoms by reducing the body’s allergic reaction
• Antihistamines – these medications are used to help the person with anaphylaxis recover more quickly from the effects of this condition (example – Benadryl)
• Steroids – these medications are also used to help the person with anaphylaxis recover more quickly from the effects of this condition (examples – Prednisone)

Medical alert bracelet

People who may be at risk of anaphylaxis need to wear a medical alert bracelet (chain or necklace), which can alert emergency medical staff and doctors that you are at risk for anaphylaxis.

Emergency medical kit

People who may be at risk for anaphylaxis may need to have an emergency medical kit which contains medicine to counteract your allergic reaction. The kit usually contains epinephrine that you inject into your arm or leg (or have a friend inject). Sometimes your doctor will also prescribe an anti-histamine to keep in the kit too. Your doctor will prescribe the dose of the medicine and show you how to use it – but always ensure your family, friends and co-workers also know how to use it too.

Alternative / complementary treatment of anaphylaxis

People who are prone to an anaphylactic reaction to a known allergen should ensure they have their medical alert bracelet and medical kit with them at all times in case of emergency.

There are no alternative / complementary treatments for anaphylaxis

Anaphylaxis is a serious, life threatening condition which requires emergency conventional treatment only.

The following alternative / complementary strategies should be used to try to strengthen the immune system only. You should discuss them with your doctor to ensure it is safe for you to try these.

Herbs

There are a few herbs which may help to strengthen the immune system (care needs to be taken if administering any type of herbal or other supplement as there could be an allergic reaction if the person is really sensitive to everything – always consult a doctor):

• Echinacea – studies show this potent herb, echinacea has a positive effect on stimulating the immune system to work properly, which in turn can reduce the asthma, eczema or allergic rhinitis symptoms which may increase the risk of an anaphylactic reaction
• Garlic – studies show this potent herb / food clears nasal congestion, reduces symptoms and prevents infection in the nasal passages and most importantly, reduce inflammation symptoms associated with sinusitis, asthma and allergic rhinitis
• Olive leaf – studies show the olive leaf herb reduces inflammation and clears up congestion in the nasal passages, reducing symptoms associated with conditions such as sinusitis, asthma and allergic rhinitis

Vitamins

Studies show that there are several vitamins which could be beneficial to increase the strength of the immune system:

• Betacarotene – the vitamin betacarotene is the precursor to vitamin A, so has the same properties on the mucous membranes
• Bioflavonoids – the antioxidants bioflavonoids, together with vitamin C, support the immune system to function correctly and reduces the severity of symptoms associated with any allergic reaction
• Vitamin A – the antioxidant vitamin A is required to keep the mucous membranes soft, moist and healthy, in order to prevent allergens from entering the body and causing an allergic reaction in the first place
• Vitamin B complex – all of the B vitamins are needed to help the immune system to function properly and reduce symptoms overall, since allergic reaction is stemmed
• Vitamin C – the antioxidant vitamin C, together with bioflavonoids, support the immune system to function more normally, by reducing the overactive response and so reduce the duration and severity of symptoms
• Vitamin E – studies show the antioxidant vitamin E helps to reduce symptoms of nasal congestion by reducing inflammation associated with allergic symptoms

Minerals

Studies show that there are several minerals which could be beneficial to increase the strength of the immune system:

• Magnesium – the mineral magnesium relaxes body tissues and may help with reduction of inflammation and anxiety associated with an allergic reaction. Emergency rooms often give magnesium sulphate to people who are having a severe asthma attack to relax the airways and help with breathing
• Selenium – studies show the powerful antioxidant selenium may reduce length and severity of symptoms
• Zinc – studies show that zinc can greatly reduce length and severity of symptoms and help to more quickly heal the inflamed nasal and lung tissue in people with asthma, allergic rhinitis and sinusitis

Other nutrients

Studies show certain nutrients have a beneficial effect on reducing length and severity of symptoms

• Alpha-lipoic acid – the nutrient alpha-lipoic acid is a potent antioxidant which can boost the immune system to help it function more normally and this can help reduce symptoms
• Essential fatty acids – studies show that the omega 3 essential fatty acids especially, can greatly reduce inflammation in the nasal passages (sinuses especially), open the airways to enable better breathing capacity and thus greatly reduce severity of symptoms. Mothers should ensure children who have allergic rhinitis or sinusitis have adequate levels of essential fatty acids in their diet to at least greatly reduce symptoms, if not prevent them from occurring in the first place
• Quercetin – studies the antioxidant nutrient quercetin assists in reducing inflammation and also reducing severity of symptoms. Quercetin is even more effective when combined with vitamin C and bioflavonoids

Dietary modifications

Dietary modifications should be adhered especially when there are severe food sensitivities present:

• Avoid foods that cause an allergy – people who have a severe allergy to specific foods need to avoid them to avoid a serious anaphylactic reaction. The most common food allergies are: peanuts, shellfish, cow’s milk, eggs, wheat and soy
• Avoid foods that are mucous forming – certain foods such as dairy, processed foods (high sugar and high fat foods) tend to cause more mucous to form which can make symptoms worse. Try to avoid all forms of dairy (except yoghurt) and all processed foods when symptoms are at their worst
• Drink more fluids – water helps to hydrate the body and moisten the mucous membranes to keep the allergens out and prevent them from causing symptoms
• Eat more garlic and onions – as much as can be tolerated either fresh, cooked or as garlic supplements; both have anti-inflammatory properties which help reduce symptoms. These are two power foods that should be eaten on a daily basis to assist with preventing symptoms (if able to be tolerated, as some people’s digestive system may not be able to handle them)
• Eat more oily fish – the fish such as salmon, mackerel, sardines, trout, tuna all contain omega 3 fatty acids which may reduce inflammation and severity of symptoms
• Eat more vegetables and fruit – they have a high content of vitamins, minerals and other nutrients such as antioxidants which may reduce severity and length of symptoms

Lifestyle modifications

There are a number of lifestyle modifications that can be followed to reduce severity and duration of symptoms:

• Avoid the allergens – if you are allergic to dust mites, use a vacuum cleaner with an air filter, if you are allergic to certain foods, avoid them, if you are allergic to other substances, avoid them as much as possible, as this will help reduce symptoms
• Rest properly – adequate amounts of sleep and rest gives the body the best chance of a quicker recovery and reduction in symptoms

Alternative treatments

• Food sensitivities – children with allergies, asthma, eczema or hay fever often have food allergies or sensitivities and much of their subsequent symptoms may be due to this sensitivity. An elimination diet needs to be followed to work out if this food is causing any of the symptoms. The most common food sensitivities that can cause behavioural problems are: cow’s milk, wheat (or gluten), oranges (and other citrus fruit), chocolate, peanuts, soy, eggs, corn, oats, apples, tomatoes. In order to test a food sensitivity, that food (and foods containing it) must be totally eliminated from the diet for two weeks (as must all foods with any artificial additives) and after that, the food can be re-introduced back into the diet to see if there are any reactions to it. This requires a lot of vigilance and strict monitoring and could be better accomplished with the help of a registered dietician or naturopath
• Immunotherapy – this involves gradually increasing doses of the substance (allergen) to which the person is allergic over time, a little at a time. This has the effect of making the immune system less sensitive to that allergen and reducing symptoms

Always ensure that you notify your medical practitioner of any supplements that you want to take – it may interfere with other medication or conditions you have. Confirm with your doctor it is safe to take before you try it.

Living with anaphylaxis

People with known allergies or have certain conditions (asthma, allergic rhinitis (hay fever), eczema, sinusitis) need to be aware that they may experience an anaphylactic reaction and should be prepared.

Strategies to reduce risk of serious anaphylactic reaction

• Alert your school or workplace – whatever your allergy, especially if it causes a serious reaction and symptoms, always let your school know (teachers, other children and the canteen) or your workplace (boss and coworkers), so that they can be aware of your allergy and keep the specific allergen away from you. Due to an increased rate of children becoming severely allergic to peanuts, some schools are now becoming peanut-free to reduce the risk of a child dying from a peanut allergy
• Avoid the allergen – to your utmost ability, avoid the allergen which may cause a serious allergic reaction and anaphylaxis symptoms. Always read labels and ask questions about food you eat. Make sure you let the restaurant staff know that you have a serious and potentially life-threatening allergic reaction to the specific food so that they can prepare your food correctly without risk. If you are allergic to certain insects, make sure you wear insect repellant. If you are allergic to latex, keep away from it and let other people know that you are allergic to it, so that they do not prepare your food with latex gloves, as this can rarely, in some people with a latex allergy, cause an anaphylactic reaction
• Inform others of your allergy – always let other people know that you have a serious allergic reaction to a certain substance and let them know what you need them to do in an emergency. This includes, teachers at school, friends, family and coworkers
• Medical alert bracelet – people with anaphylaxis can also wear a medical alert bracelet to let other people know what substance they are allergic to and what medicine they need to counteract their allergy
• Medical emergency kit – always have a medical emergency kit with medication (epinephrine and an antihistamine) close by and show your teachers, coworkers, friends and family how to use the medication in case of an emergency

Caring for someone with anaphylaxis

Partner

If your partner has a serious allergy, you can support them through the following:

• Avoid contact with the allergen – you also need to reduce your contact with the allergen (especially if it is a food or latex allergy) because in some people, just coming into contact with someone else who has been in contact with the allergen may spark an anaphylactic reaction. While this is rare, it does happen and it is advisable to err on the side of caution
• Keep the home an allergy free zone – remove all possibility of contact with the allergen in the home, by ensuring any processed foods do not contain the allergen and are not processed on the same area that the allergen is processed, keep latex away (if latex allergy is the problem) to reduce likelihood of a severe allergic reaction
• Learn about their medication – find out how to administer the medication in the medical emergency kit if your partner is in an emergency situation, where they have come into contact with the allergen and are having a serious anaphylactic reaction. In addition, call an ambulance on 000 if this occurs

Friends

If your friend has a serious allergy to an allergen, you can support them through the following:

• Avoid contact with the allergen – if your friend has a serious and potentially life threatening allergic reaction to a specific substance, keep away from that substance prior to seeing your friend as you may unwittingly cause them to have a reaction
• Learn about their medication – find out how to administer the medication in the medical emergency kit if your friend is in an emergency situation, where they have come into contact with the allergen and are having a serious anaphylactic reaction. In addition, call an ambulance on 000 if this occurs

Parents

If your child has a serious allergy to an allergen, you can support them through the following:

• Avoid contact with the allergen – you also need to reduce your contact with the allergen (especially if it is a food or latex allergy) because in some people, just coming into contact with someone else who has been in contact with the allergen may spark an anaphylactic reaction. While this is rare, it does happen and it is advisable to err on the side of caution
• Inform the school – if your child has a serious allergic reaction to any substance, which may develop into anaphylactic shock, it is really important you inform the school teachers who can inform other parents and their children to help reduce your child’s contact with the allergen. Some schools may request the children in your child’s class to avoid bringing in the allergen to avoid likelihood of your child having a reaction. The teachers will also need to learn how to administer the medication (in the emergency medical kit) if required
• Keep the home an allergy free zone – remove all possibility of contact with the allergen in the home, by ensuring any processed foods do not contain the allergen and are not processed on the same area that the allergen is processed, keep latex away (if latex allergy is the problem) to reduce likelihood of a severe allergic reaction
• Learn about their medication – find out how to administer the medication in the medical emergency kit if your child is in an emergency situation, where they have come into contact with the allergen and are having a serious anaphylactic reaction. In addition, call an ambulance on 000 if this occurs

References

Last reviewed and updated: 14 May 2024