Anaphylaxis: what is it and how do we treat it?
Anaphylaxis is the most severe of the allergic reactions. Because anaphylaxis often comes on suddenly and can progress quickly, it is a very dangerous condition. The quicker anaphylaxis is treated, the better! That’s why people who have anaphylaxis or are at risk for anaphylaxis must know how to reduce their risk by preventing exposure to triggers, knowing how to recognize early signs and be prepared for emergency treatment at any time.
What can cause anaphylaxis?
In children, foods (such as egg, milk, peanuts, nuts, fish, shellfish, sesame, soya and wheat) are the most common cause of anaphylaxis. In adults medications may be more important. More common medication causes include antibiotics, pain medication and drugs used during anaesthesia. Bee venom is the most common cause of anaphylaxis due to insect stings in South Africa. Some people have anaphylaxis without any cause being identified. This is called idiopathic anaphylaxis and is a problem, because the person doesn’t know what triggers to avoid.
How do I know if this is anaphylaxis?
Anaphylaxis usually occurs soon after exposure to a trigger, within 15 minutes to 1 hour. So the history of coming into contact with a possible allergen is very important. Skin signs are the most common signs of an allergic reaction. If skin signs occur on their own this is a milder reaction, not anaphylaxis; a combination of signs in different body systems is characteristic of anaphylaxis.
The following body systems can be involved. Get a personalised “action plan” from your doctor and ask him/her to go through what signs are a mild reaction and how to know whether a reaction is severe.
Skin signs include flushing, redness, itching, hives and swelling especially of the face.
Stomach symptoms include cramps, nausea, vomiting and diarrhoea.
Chest and lung involvement can cause swelling of the upper airways such as the tongue, the back of the throat and the area of the voice box or larynx. This may start with a hoarse voice and a persistent dry cough and then progress to throat tightness causing difficulty breathing. The airways of the lung may be involved causing chest tightness and a wheezing noise.
Symptoms involving the heart and circulation include a sudden drop in blood pressure, irregular heartbeat and general collapse.
Anaphylaxis can be treated!
If someone with anaphylaxis realises they are having an attack and treats it quickly, then it usually goes away quite quickly. Once it progresses it gets more difficult to treat. Adrenaline is your bodies “flight or fight” hormone that is its natural response when you have anaphylaxis. Extra adrenaline, given as an injection into a muscle as soon as anaphylaxis occurs is the best treatment for the serious effects of anaphylaxis. If someone has an emergency injection with them, either assist them to inject it into the large muscle of their thigh, or give it to them yourself. Help avoid shock by lying the person down with their feet raised off the ground. Do not give any medication by mouth if the person is having difficulty breathing. Other treatments that can help after adrenaline has been given include antihistamine and steroids. Call for an ambulance as soon as possible and get the person to hospital.
Anaphylaxis can be prevented!
The best strategy for someone who knows they have a severe allergy is to avoid the thing they are allergic to. People with food allergies must learn to read food labels carefully. People who have a reaction for the first time should try to identify the trigger and have tests done to confirm that this was the cause. An allergy trained doctor will take a good history, do allergy tests and possibly even do specific very controlled “challenges” to pinpoint the trigger and help you avoid further exposure.
People at risk for anaphylaxis must be taught to immediately recognise the earliest signs of anaphylaxis. They are given an emergency action plan that describes the signs of a mild attack and a severe attack, and taught the correct response for either possibility.
People at risk of anaphylaxis must wear a Medic Alert disc, must carry emergency treatment with them at all times and know how to inject themselves with adrenaline for a severe attack.
Adrenaline is the best treatment
In your doctor’s surgery or in the Emergency Department of a hospital, adrenaline is injected using a syringe and needle. For non-medical people adrenaline can be given using an automatic injection device or “pen”. The pen is swung gently against the outer thigh until a click is heard and adrenaline will automatically be injected into the person. Get your doctor to demonstrate this to you with a “dummy” practice pen. The only adrenaline auto injector in South Africa at present is the Epipen®. Epipen® comes in 2 strengths, Epipen® junior for children between 8 and 25 kg and Epipen® for adults and children greater than 25 kg. Large adults may need 2 Epipens®.
Where Epipen® is not available, patients should carry a vial of adrenaline and a needle in a secure case and will require extensive education and training to teach them to draw up and give the correct dose (0.01ml/kg) in an emergency.
Children and anaphylaxis
Children must be taught to avoid foods to which they are allergic. The child’s school is your best partner in keeping your child safe! They should have a copy of the action plan. The Epipen® or adrenaline emergency kit, as well as an antihistamine syrup, must be with the child at school and teachers must know where the emergency medication is kept. The teachers must be fully informed about the allergies and management plan, and be trained to give adrenaline in the case of an emergency.
Where schools have children who are allergic to a specific food, in particular peanuts, it may be wise to prohibit that specific food from being bought to school by other school children.