Anaphylaxis

Anaphylaxis symptoms can happen within seconds of exposure to an allergen, but may also take longer than half an hour to present.  

Symptoms of anaphylaxis include:

• a rapid, weak pulse 

• sudden difficulty breathing

• swelling of the face, lips, tongue and throat

• difficulty swallowing or speaking

• large hives or a rash on the body

• flushed, red skin

• abdominal cramps, nausea and vomiting

• dizziness and fainting

• collapse and unconsciousness

There are 2 main types of anaphylactic reaction:

• uniphasic – symptoms come on quickly and rapidly get worse, but once treated, the symptoms go and don’t return

• bi-phasic – symptoms may be mild or severe to start with, followed by a period of time when there are no symptoms. Symptoms may then return and get worse

In severe cases, there’s a risk of a dramatic fall in blood pressure and the narrowing of airways (anaphylactic shock). Someone suffering from an anaphylactic shock may become weak and floppy, have trouble breathing, and lose consciousness.

Anaphylaxis is caused by an overreaction of the immune system to an allergen or trigger. The immune system rapidly releases certain chemicals, such as histamine, which cause the symptoms of anaphylaxis. 

Common anaphylaxis triggers include: 

• foods – including nuts, milk, fish, shellfish, eggs, and some fruits

• medicines – including some antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin

• insect venom – particularly wasp and bee stings

• general anaesthetic

• contrast agents – dyes used in some medical tests

• latex – a type of rubber found in some rubber gloves and condoms

• exercise – exercise-induced anaphylaxis is uncommon and not well-understood 

Patients with the rare immune disorder mastocytosis are at increased risk of anaphylaxis due to an abnormally high number of mast cells – immune cells that release histamine during allergic reactions.

Sometimes a patient experiences anaphylaxis, and no trigger can be identified. This is called idiopathic anaphylaxis. 

Anaphylaxis is a medical emergency and is diagnosed by observing the symptoms present. 

Following an acute episode, we recommend making an appointment with one of our expert allergists in our Allergy centre. Our allergists will diagnose anaphylaxis by talking to you at your initial consultation about your recent reaction, medical history, and any potential triggers. 

Other tests that may be carried out include:

• blood tests to look for the enzyme tryptase, which is released during anaphylaxis and can stay at high levels in the blood for up to 3 hours

• skin prick tests – small amounts of allergens are pricked into the skin to look for a reaction and identify triggers 

• food challenge tests – small amounts of food are given in a controlled setting to look for a reaction

• blood tests to look for specific antibodies to certain allergens

Many conditions have signs and symptoms similar to those of anaphylaxis. Your consultant may want to carry out other tests to rule out other conditions.

The best way to prevent anaphylaxis is to identify triggers and stay away from known allergens. 

If you have a known trigger, you should: 

• carry any prescribed medication, such as autoinjectors, with you and teach friends and family how to use them 

• check the expiry date on any autoinjectors 

• consider wearing a medical alert bracelet or necklace to tell other people about your allergy in case of an emergency

• seek medical help as soon as you notice symptoms, even if they’re mild

The complications of anaphylaxis are severe and potentially life-threatening. Untreated anaphylaxis can lead to respiratory failure, cardiac arrest and organ failure. Anaphylaxis should always be treated as an emergency. 

Anaphylaxis is a medical emergency and may need rapid treatment with epinephrine (also known as adrenaline), which can be given by injection. 

Following an acute episode of anaphylaxis, our allergists will be able to help you identify triggers and manage and reduce the risk of future reactions.

Treatment and management of anaphylaxis may include: 

• carrying an epinephrine auto injector (often referred to as an EpiPen) 

• oral steroids or oral antihistamines

• desensitisation therapy – a series of injections is given that work to change your body’s natural reaction to a trigger and reduce symptoms of severe reactions

For patients who have frequent reactions without an identifiable trigger, a course of regular treatment – such as daily oral steroids over a few weeks or months – may be needed to prevent further episodes and help stabilise the condition.

At Welbeck, our allergists are experts in their field and are dedicated to providing world-class care to every patient.

With access to colleagues across other specialties, our consultants are also able to refer within the Welbeck ecosystem if required to ensure you receive the treatment you need as quickly as possible, all under one roof.  

All appointments, testing, treatment, and follow-up appointments take place within our state-of-the-art facilities, enabling us to deliver accurate diagnostics and advanced treatments.

Your health is important to us, so we strive to offer same-day appointments whenever possible.

Our consultants are recognised by the major health insurance companies. If you have private health insurance, your treatment at Welbeck can begin once you have obtained authorisation. We also provide care to self-paying patients. Learn more about the different payment options at Welbeck.

Get in touch today to book an appointment.