Anaphylaxisis a life-threatening allergic reaction that can be triggered by exposure to many different substances (allergens).
The most common allergies that can produce anaphylaxis are to drugs, insects stings, foods, and latex.
Immunological Causes
Yourimmune systemprotects you from foreign substances.
Illustration by Verywell
On future exposures, these antibodies bind to the substances and also to receptors on mast cells and basophils.
This triggers the release of the mediator chemicals that promote an inflammatory reaction.
Histamineand other mediators cause the blood vessels to dilate so more fluid enters the tissues, leading to swelling.
In anaphylaxis, the chemicals are released throughout the body and affect many different systems.
Low blood pressure, hives, and difficulty breathing are seen.
An anaphylactic reaction does not usually occur the first time you are exposed to an allergen.
The next time you are exposed to the allergen you may have an allergic reaction.
Anaphylaxis is rare but can occur anytime after you are sensitized.
Sometimes these chemicals are directly triggered to be released, without prior exposure or development of antibodies.
This is called an anaphylactoid reaction and is more often seen in reactions to IV contrast medium and opioids.
Common Triggers
Anaphylaxis can occur in response to almost any allergen.
However, common respiratory allergies such as hay fever and animal dander rarely cause anaphylaxis.
A large percentage of cases of anaphylaxis can’t be linked to a specific allergen and are called idiopathic.
Fire ants can also produce the reaction.
The demand for latex soared in the 1980s as glove use was required in more areas of health care.
The latex used was high in the protein that triggers latex allergy.
The gloves currently produced are lower in protein.
The cause of exercise-induced anaphylaxis is unknown.
An example of this is wheat-dependent exercise-induced anaphylaxis (WDEIA).
Some people with EIA associate it with eating, but there is no specific food that triggers the symptoms.
Dust mites are a common cause of allergic diseases.
Symptoms of OMA typically occur within a few minutes to hours after eating a food contaminated with dust mites.
Cold-Induced Urticaria/Anaphylaxis
Rarely, exposure to cold can produce anaphylaxis.
They then can develop anaphylaxis when they eat red meat.
People with allergies to the common triggers of anaphylaxis are more at risk.
If you previously had an anaphylactic reaction, you are at greater risk of having one again.
Future reactions may be even more severe.
People with even mild asthma are more at risk of severe allergic reactions, including anaphylaxis.
Mastocytosisis a rare condition that develops due to a mutation in a gene.
These cells can accumulate in the skin, internal organs, and bones.
Allergic Reaction vs. Anaphylaxis
Anaphylaxis is a severe allergic reaction that affects two or more organ systems.
After using the epinephrine, seek medical attention right away as the effects wear off within 20 minutes.
Anaphylaxis can return, so further treatment and observation will be necessary.
Frequently Asked Questions
Anaphylaxis is a potentially life-threatening allergy affecting the body as a whole.
Up to 5% of people will experience anaphylaxis at some point in their lives.
As with allallergies, anaphylaxis pops up if the immune system regards an otherwise harmless substance as harmful.
Food allergies to nuts, shellfish, milk, and eggs are the most common triggers in children.
Anaphylaxis requires emergency medical care.
Intravenousantihistaminesandsteroidscan improve inflammation, whilebeta-agonistslike albuterol can help ease breathing.
If anaphylaxis isn’t treated, death can occur within minutes or hours.
Anaphylaxis can also cause suffocation if the swelling of the throat blocks the airways.
Even so, less than 1% of anaphylactic events end in death.
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