Anaphylaxis
Symptoms, Causes and Emergency Treatment of Severe Allergic Reactions
Anaphylaxis is a severe, potentially life-threatening allergic reaction that requires immediate medical attention. It can develop rapidly and affect the airway, breathing and circulation.
At the London Allergy and Immunology Centre, we provide specialist assessment, diagnosis and long-term management of patients at risk of anaphylaxis, including allergy testing, adrenaline auto-injector training and personalised care plans.
Anaphylaxis is a medical emergency that can develop rapidly and requires immediate treatment with adrenaline.
What is Anaphylaxis?
Anaphylaxis is a severe systemic allergic reaction caused by rapid activation of the immune system, typically involving IgE-mediated hypersensitivity.
It can occur within minutes of exposure to an allergen and may affect multiple organ systems, including the skin, respiratory system, gastrointestinal tract and cardiovascular system.
✔ Can affect breathing and blood pressure
✔ Requires immediate treatment with adrenaline
✔ Delayed treatment increases risk of severe outcomes
Symptoms of Anaphylaxis
Symptoms usually develop within minutes but can sometimes be delayed.
Skin Symptoms
✔ Hives (urticaria)
✔ Swelling (angioedema)
✔ Flushing or itching
Respiratory Symptoms
✔ Difficulty breathing
✔ Wheezing or chest tightness
✔ Throat swelling or voice changes
Circulatory Symptoms
✔ Dizziness or fainting
✔ Low blood pressure
✔ Rapid or weak pulse
Gastrointestinal symptoms such as nausea, vomiting or abdominal pain may also occur.
Common Causes of Anaphylaxis
Food Allergies
Peanut, tree nuts, milk, egg, shellfish, sesame
Insect Stings
Bee and wasp venom reactions
Medications
Antibiotics, NSAIDs and anaesthetic agents
Other Triggers
Latex, exercise-induced anaphylaxis
Emergency Treatment of Anaphylaxis
First-line treatment is:
✔ Lie flat with legs elevated (if possible)
✔ Repeat adrenaline after 5–10 minutes if needed
✔ Seek urgent medical care even if symptoms improve
Needle-Free Adrenaline Treatment: EurNeffy Nasal Spray
EurNeffy is a newer form of adrenaline (epinephrine) treatment delivered as a nasal spray, designed as an alternative to traditional adrenaline auto-injectors. It represents an important development in the management of anaphylaxis, particularly for patients who are anxious about injections or find auto-injectors difficult to use.
The medication is administered into the nose rather than by injection, allowing rapid absorption through the nasal mucosa. This can make it easier to use in emergency situations, especially for children, caregivers or untrained individuals.
✔ Designed for rapid use in emergencies
✔ May improve confidence and adherence in patients with needle anxiety
✔ Simple administration without the need for injection technique
How Does EurNeffy Work?
Like traditional adrenaline auto-injectors, EurNeffy delivers epinephrine, which works by:
✔ Increasing blood pressure
✔ Reducing swelling of the throat and tongue
✔ Counteracting the allergic reaction rapidly
Important Considerations
While EurNeffy is a promising development, it is important to note:
✔ Patients must still have a clear anaphylaxis action plan
✔ Emergency services (999) should always be called after use
✔ Suitability depends on individual clinical assessment
At present, adrenaline auto-injectors such as EpiPen or Jext remain the standard first-line treatment for anaphylaxis in the UK. However, needle-free options such as EurNeffy may play an increasing role in the future as clinical experience and availability expand.
At the London Allergy and Immunology Centre, we provide individualised advice on emergency allergy treatment, including training on adrenaline use and discussion of emerging treatment options where appropriate.
Diagnosis and Allergy Testing
After an episode of anaphylaxis, identifying the trigger is essential.
Clinical History
Detailed review of reaction timing and suspected trigger
Allergy Testing
Skin prick testing and specific IgE blood tests
Advanced Testing
Component-resolved diagnostics where appropriate
Long-Term Management
✔ Prescription of adrenaline auto-injectors
✔ Training on how and when to use adrenaline
✔ Trigger avoidance strategies
✔ Regular specialist follow-up
EpiPen® Support & Training App
The EpiPen® app provides step-by-step guidance, reminders and emergency support for patients at risk of anaphylaxis.
EpiPen and Jext mobile apps featuring instructions and reminders for emergency allergy treatment
Book an Anaphylaxis Assessment
Specialist diagnosis and management for severe allergic reactions.