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What is Anaphylaxis?

Anaphylaxis is a severe allergic reaction which may be potentially life-threatening. It is life threatening because the allergic reaction affects your vital organs such as the windpipe, lungs, heart or gastrointestinal tract.

What Causes Anaphylaxis?

The common causes of anaphylaxis worldwide include food allergies (especially peanut allergy), drug allergies and insect venom allergy.

In Singapore, our most common causes of anaphylaxis in adults are:

  • Food allergy – especially from eating shellfish, limpets (aquatic snails) and bird’s nest
  • Insect venom allergy – caused by stings from bees, wasps or hornets

Anaphylaxis due to drug allergy is less common locally.

​Symptoms of Anaphylaxis

Recognising Mild Allergic Reactions
Not all allergic reactions will result in anaphylaxis. Mild allergic reactions can be treated with antihistamines alone. Signs and symptoms of mild reactions include:

  • Urticaria (also known as “hives” or “wheals”)
  • Mild swelling of the eyes or lips
  • Tingling sensation around the mouth or of the tongue
  • Itchy, watery eyes
  • Sneezing, blocked nose, nasal discharge

Recognising Anaphylaxis
It is important to recognise the symptoms of anaphylaxis and seek immediate medical attention.

Skin flushing, widespread hives, with any of the following:

  • Throat tightness with altered voice, difficulty in speaking or swallowing
  • Chest tightness, difficulty in breathing
  • Rapid heart beat (palpitations)
  • Giddiness, feeling faint or losing consciousness
  • Abdominal pain
  • Vomiting or diarrhoea

How is Anaphylaxis Diagnosed?

An allergist will determine the cause(s) of your anaphylaxis after reviewing your symptoms and history.

Skin tests or blood tests may be performed to help with the diagnosis.

You will also see a Clinical Immunology / Allergy Nurse Clinician, who will provide you with more information on how to avoid your allergic triggers.

How is Anaphylaxis Treated?

All patients with anaphylaxis will be prescribed with an epinephrine autoinjector (Epipen®), except for patients with drug-related anaphylaxis. You are encouraged to carry the epinephrine autoinjector with you at all times.

It is also advisable to inform your family members, employers or school personnel about your anaphylaxis. By doing so, they can watch for symptoms and help you avoid your allergy triggers.

Anaphylaxis Action Plan

Take an antihistamine when mild symptoms occur. Be on the alert for worsening symptoms.

When symptoms worsen or if you develop anaphylaxis:

A. Use the Epipen® Autoinjector

  1. Remove the Epipen® from its protective casing and pull off the blue safety release cap.
  2. Place the orange tip against your outer thigh
  3. Push down firmly until there is a “click” sound and hold the Epipen® in place for at least 3 seconds. Remove Epipen® from your thigh.

​B. Call for Emergency Help

Call 995 for an ambulance. Go to the nearest medical facility or hospital even if your symptoms have improved or subsided.

EpiPen, EpiPen Jr, EpiPen 2-Pak, EpiPen Jr 2-Pak, Never-See-Needle, MYLAN and the Mylan logo are registered trademarks of Mylan Inc. Blue to the sky, orange to the thigh is a registered trademark of Mylan Specialty L.P. EPI-2020-0273

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