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Anaphylaxis Reactions and Common Triggers

What is Anaphylaxis?

The Mayo Clinic states that Anaphylaxis is a severe allergic reaction, to the point of life threatening. It happens when someone is put in contact with something they are allergic to.

Common Triggers

Anaphylaxis is life threatening, the CFP outlines that death due to an Anaphylactic reaction usually occurs because of airway compromise (Inability to breathe) or cardiovascular collapse. In an Investigation on Anaphylaxis affiliated with Columbia University, Anaphylactic reactions that occur shortly (few minutes) after ingesting food vs. longer (several hours) can be equally as severe/life threatening.

According to the NHS, Common Triggers of Anaphylaxis include:

  • Foods such as nuts (peanuts), milk, shellfish, eggs and some fruit.

  • Medicines such as Antibiotics and Aspirin.

  • Insect Stings (Ex. Wasp/Bee Stings).

  • General Anaesthetic, being medicines that are used to put individuals into a state of "Controlled Unconsciousness".

  • Contrast Agents, The dyes of medical tests used to improve visibility of different body parts during a scan.

  • Latex, type of rubber.


The cause of these life threatening reactions comes from the immune system, who's main purpose is to defend against foreign substances. In certain cases, the human body isn't able to identify whether a substance is harmful or harmless, and may overreact. The Mayo Clinic expands as even after an individual is exposed to an allergen and has a mild reaction, it's still possible that they could experience a more severe reaction (Anaphylaxis) upon a subsequent exposure.

The Mayo Clinic says that possible symptoms of an Anaphylactic reactions can occur from minutes to half an hour or longer after exposure to an allergen. A few possible symptoms include:

  • Hives, Itching, or other skin reactions.

  • Low Blood Pressure (hypotension)

  • Difficulty breathing due to constriction of airways/swollen tongue or throat.

  • Weak/rapid pulse.

  • Nausea, vomiting, diarrhea.

  • Dizziness/fainting.

Other symptoms presented by the NHS include feeling lightheaded, having an increase in blood pressure, clammy skin, confusion/anxiety or loss of consciousness.


Diagnosis is often needed if an individual experiences a severe allergic reaction without knowing the cause of said reaction. The Mayo Clinic says that Doctors must ask their patients about reactions to common triggers of Anaphylaxis to narrow down the diagnosis. Different conditions besides Anaphylaxis are similar in the symptoms that are caused, so doctors must also eliminate separate conditions to confirm a diagnosis of Anaphylaxis.

Other tools to confirm diagnosis include:

  • Blood tests that gauge levels of tryptase - an enzyme known to be present at elevated levels after Anaphylaxis.

  • Skin/Blood tests to confirm triggers.

Although there is usually a known allergen causing Anaphylactic reactions, sometimes, the NHS says there is an occurrence of Idiopathic Anaphylaxis. Idiopathic Anaphylaxis is when there is no clear trigger of a severe allergic reaction.

In an Article on Idiopathic Anaphylaxis, it says that the cases are rare and the type of Anaphylaxis is described to be where "triggers cannot be identified despite a detailed history and careful diagnostic assessment". Over 60% of cases are identified in females and it is much more common in adults rather than children. According to the CFP " "Up to 20% of anaphylactic reactions are idiopathic".


If you know you have an allergy to something, there are measures you can take to prevent Anaphylactic reactions. Some tips/techniques highlighted by The Mayo Clinic include:

  • If you have a known allergy to a substance/medication/food, wear a medical alert bracelet or another identifying accessory to help others awareness of your allergy.

  • Always carry medications to combat serious allergic reactions with you at all times. Ensure that the medication is up to date and the filled.

  • Let your doctor(s) know if you have an allergic reaction or need to identify the source of a reaction.

  • Be aware of your surroundings and potential risks.

When you or someone you know is having an Anaphylactic Reaction, there are many steps to do depending on the situation.

  • If one's heart stops beating or one stops breathing, they may be given CPR (Cardiopulmonary Resucitation).

  • Epinephrine or Adrenaline is used to reduce the allergic response.

  • If a person stops or is having difficulty breathing, they may be given oxygen.

  • Antihistamines and cortisone administered intravenously reduces inflammation in the throat and other air passages to ease breathing.

  • Albuterol, a beta-agonist (Medicine that relaxes the airway), to ease breathing.

Epinephrine Injections are a common treatment to Anaphylactic reactions and they are potentially life saving. Yet, according to the CFP, an overdose of the substance can cause "coronary artery dissection, acute myocardial infarction, cardiomyopathy, arrhythmias, and death." A 2010 study found that the rate of incidence of improper administration of epinephrine leading to life-threatening effects was 2.4%.

If you come across someone who is showing signs/symptoms of an anaphylactic reaction...

  1. Call 911, emergency responders. Explain the situation.

  2. Administer Epinephrine via an autoinjector, if it is present, into the person's thigh.

  3. Help the person lay down and elevate their lays (Increase circulation to upper body).

  4. Check that the person is breathing and has a pulse, perform CPR and other known first aid techniques if necessary and you are confident with your abilities.

Article Contributors: Mina Chong, Edie Whittington

Article Editor: Stephanie Sahadeo