About Anaphylaxis

Anaphylaxis refers to a generalized allergic reaction which is rapid in onset, and which may be severe. Although rare, some cases may lead to long term sequels or even cause death. It is estimated that between 3 and 30 in 100.000 persons per year will suffer an anaphylactic crisis, so you can see it is not very common.
By definition, at least two body systems should simultaneously be involved in this syndrome. The most common one is the skin in the form of itching, urticaria, generalized redness or angioedema; it is involved in 80% of cases. Other systems which may be involved are: the respiratory system (in the form of acute rhinitis, asthma or upper airway angioedema), the digestive track (with nausea, vomiting, stomach cramps or diarrhea), or the cardiovascular system (with palpitations, increased heart rate or fall in blood pressure). This may lead to dizziness, loss of consciousness, and in the worst scenario, to cardiac or respiratory arrest.
The most common causes are food in pediatric patients and drugs in adults. The third cause of anaphylaxis is bee and wasp stings, due to venom allergy.


The diagnosis of anaphylaxis is based on symptoms and signs and requires immediate action, so no laboratory test can aid in decision making in the acute moment. Some laboratory tests, such as serum tryptase levels, may help confirm an anaphylactic episode.
Underlying allergies, and even other conditions such as systemic mastocytosis, should be adequately assessed.


When acute anaphylaxis is suspected, immediate medical attention should be seeked. Patients who have been prescribed self-injected adrenaline (epinephrine) should use it if they have developed symptoms suggestive of anaphylaxis (always according to their personalized management action plan).
Long term management is crucial in these patients. This means that they should be urgently referred to an allergy unit in order to assess possible causes and to be trained on the recognition and management of the acute anaphylaxis.


If you have suffered an anaphylaxis, please consider carefully the following recommendations:

  • An allergy specialist should evaluate you to help find and confirm the triggering allergies accountable for the anaphylaxis
  • Ask for specific written information on what you should avoid, i.e. if you have a food allergy, you should know which cross-reactive food-stuffs not to eat
  • Carry your emergency kit including adrenaline (epinephrine) at all times, and use according to your personalized management plan
  • Ask your specialist if you should wear a anaphylaxis alert stating what you are allergic to
  • Always carry with you a copy of your medical report
  • Inform your family, friends and colleagues about your condition, so they can help in case of a new anaphylaxis