World Allergy Week: Life-threatening allergic reaction anaphylaxis under the spotlight
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The week marks World Allergy Week, an annual event that aims to raise awareness around allergies and their often-serious impact on people. This year’s campaign is focused on educating people about anaphylaxis.
Professor Mike Levin, CEO of the Allergy Foundation of South Africa (AFSA) – the organisation driving the awareness campaign in SA – explains that anaphylaxis is the most severe of the allergic reactions, and because its onset is often sudden and deterioration can be rapid, it is a very dangerous condition.
“The quicker anaphylaxis is treated, the better! We can save lives if everyone learns the early signs of anaphylaxis and is able to recognise it and respond fast. That is why it is essential that people at risk, as well as the parents of children who suffer from this condition, must know how to reduce the risk, how to recognise early signs, and how to administer emergency treatment if required,” said Levin.
What causes anaphylaxis?
According to Levin – who is also head of the division of asthma and allergy in the Department of Paediatrics and Child Health at the University of Cape Town – for many people, foods such as egg, milk, nuts, fish, shellfish, sesame, soya and wheat are the triggers for anaphylaxis. In other people, medications may be the cause, whilst for some it may be triggered by air-borne or occupational allergens, an allergy to natural rubber latex, an allergy to insect stings (e.g bee or wasp stings) or even to physical factors such as extreme cold.
Overall, bee venom is the most common cause of anaphylaxis in South Africa, though severe reactions to food allergens are on the increase.
How to identify the symptoms of anaphylaxis?
Anaphylaxis usually occurs soon after exposure to an allergen (within 15 minutes to 1 hour). Some of the first signs of an anaphylactic reaction may present themselves as typical allergy symptoms – a runny nose or skin rash. In fact, reactions of the skin – such as flushing, redness, itching, hives and swelling – are usually some of the earliest signs. However, within a short time, more serious signs appear, such as stomach cramps, nausea, vomiting and diarrhoea, swelling of the tongue, the back of the throat and the upper airways.
These reactions may start with a hoarse voice and a persistent dry cough and then progress to a tight throat, tight chest and difficulty breathing. Further frightening symptoms include a sudden drop in blood pressure, an irregular heartbeat and general collapse.
How is anaphylaxis treated?
According to Professor Claudia Gray, a paediatrician and allergist and executive committee member of Allergy Society of South Africa (ALLSA), if someone with anaphylaxis realises that they are having an attack and treats it speedily, it can usually be controlled quickly. If allowed to progress untreated, it becomes more difficult to control the allergic reaction, with possible serious results.
“People at risk for anaphylaxis must be taught to immediately recognise the earliest signs so that they can react swiftly. Sufferers should wear a medical emergency disc or band (bracelet or necklace) and must ensure that they always carry emergency adrenaline treatment, for example an adrenaline auto-injector, with them and know how to inject themselves. The auto-injectors generally come in two strengths – one for children between 8 and 25kg and another for people weighing more than 25 kg. Large adults may need two doses,” said Gray.
How to help someone else experiencing anaphylaxis
“If someone has an emergency injection with them and is unable or unsure about administering it themselves, you can help them to inject it into the large muscle of their thigh. Parents need to educate their children on how to eventually do this themselves but will need to assist them initially, until they are older.”
“Help avoid shock by lying the person down with their feet raised off the ground. Other treatments that can help after adrenaline has been given include antihistamines and asthma pumps, but do not give any medication by mouth if the person is having difficulty breathing. 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 trigger they are allergic to. People with food allergies must learn to read food labels carefully and those who have a reaction for the first time must try to identify the trigger and have tests done to confirm the cause. An allergist will check medical symptoms and may recommend allergy tests and controlled “challenges” to pinpoint the trigger and help avoid further exposure.
Covid-19 vaccine induced anaphylaxis – what you need to know
There have been reported cases of some people experiencing anaphylaxis after receiving the Covid-19 vaccine. Gray and Levin agree that the instances are extremely rare, with the occurrence of anaphylaxis estimated at 1.31 in 1 million doses given.
“Although the specific vaccine component causing the anaphylaxis has not been identified, people who have a history of a severe allergic reaction to any prior vaccine should be referred to an allergist for further evaluation prior to getting the Covid-19 vaccination. Anyone who has a reaction of any severity within 4 hours of receiving the first Covid-19 shot, should not get the second shot. People with food allergies and environmental allergies and asthma can safely be given the Covid-19 vaccine without any additional risk. The Covid-19 vaccines are administered in a health care setting where anaphylaxis can be treated speedily should it occur – but again, I reiterate that instances are rare,” concludes Gray.