Anaphylaxis is an allergic reaction caused by different allergenic substances such as medications, foods, insect bites, and others. It can be life-threatening if it is not treated immediately.

Next, we will explain what amphilaxis or anaphylaxis is , what its most common causes are, what symptoms it causes, how the diagnosis is made, what treatment is applied to alleviate its symptoms, what the prognosis can be and what precautions can be taken to avoid it.

Anaphylaxis: What is it?

Anaphylaxis is a rapidly progressive and life-threatening allergic reaction . The immune system responds to substances that are otherwise harmless to the environment (allergens).

Unlike other allergic reactions, however, anaphylaxis can kill. The reaction can begin within minutes or even seconds after exposure, and progresses rapidly to cause constriction of the airways, skin and intestinal irritation, and altered heart rhythms. In severe cases, it can result in complete airway obstruction, shock, and death.

Common Causes

Allergens are more likely to cause anaphylaxis if introduced directly into the circulatory system by injection. However, exposure by ingestion, inhalation or skin contact can also cause anaphylaxis. In some cases, anaphylaxis may develop over time from less severe allergies.

Anaphylaxis is most often due to allergens in food, drugs, and insect venom . Specific causes include:

  • Fish, seafood and molluscs.
  • Nuts and seeds.
  • Bee, wasp or hornet stings .
  • Meat tenderizer daddy.
  • Vaccines, including flu and measles vaccines.
  • Penicillin.
  • Cephalosporins.
  • Streptomycin.
  • Gamma globulin .
  • Insulin.
  • Hormones (ACTH, thyroid-stimulating hormone)
  • Aspirin and other NSAIDs .
  • Latex, from exam gloves to condoms, for example.

Exposure to cold or exercise may trigger an anaphylactic response in some people.

Symptoms of anaphylaxis

Symptoms develop rapidly, usually within seconds or minutes. Anaphylaxis may include any of the following symptoms listed below. However, not all of them need to be present.

  • Abdominal pain .
  • Anxiety and/or feeling of confusion.
  • Chest discomfort or tightness.
  • Diarrhea.
  • Cramps .
  • Wheezing.
  • Difficulty breathing , coughing, wheezing or high-pitched breathing sounds.
  • Difficulty swallowing.
  • Dizziness.
  • Hives, itching, redness of the skin.
  • Nasal congestion.
  • Nausea and vomiting .
  • Palpitations.
  • Poor articulation of language.
  • Swelling of face and eyes .
  • Swelling and irritation of the tongue and/or mouth
  • Swelling of the breasts.
  • Loss of consciousness.


The anaphylactic reaction is diagnosed based on the rapid development of symptoms in response to a suspected allergen . Identification can be made with the RAST test. The RAST test is a blood test that identifies IgE (immunoglobulin type E) reactions to specific allergens. Skin testing can be done for less severe anaphylactic reactions.


Emergency treatment of anaphylaxis involves the injection of adrenaline (epinephrine) which constricts the blood vessels and counteracts the effects of histamine. Oxygen may be given, as well as intravenous replacement fluids.

Antihistamines can be used for the rash and aminophylline for bronchial constriction. If the upper airway is blocked, a breathing tube or tracheostomy tube may be needed.

Prognosis and expectations

Anaphylaxis can be fatal without timely treatment. Symptoms usually improve with appropriate therapy, so it is important to act immediately .

The speed of symptom development is an indication of the possible severity of the reaction: the faster the symptoms develop, the more severe the final reaction. Seeing a doctor urgently and following up closely reduces the likelihood of death in anaphylaxis. Therefore, most people who receive prompt treatment recover completely .

If not acted upon quickly, anaphylaxis can block the airway areas, causing cardiac arrest, respiratory arrest or fatal anaphylactic shock .

Prevention: what can we do to avoid it?

The main reliable method of preventing anaphylaxis and allergic reactions is to avoid the allergic trigger, such as foods and medications, that have caused an allergic reaction in the past.

For insect allergies, this requires recognition of probable nesting sites. The prevention of food allergies requires knowledge of the prepared foods or dishes in which the allergen is likely to occur, and careful questioning of the ingredients when eating outdoors .

If you have a child who is allergic to certain foods, you can introduce one new food at a time in small amounts so that an allergic reaction can be recognized.

People prone to anaphylaxis should carry an “Epipen” or “Ana-kit”, which contains a dose of adrenaline ready for injection. As well as a medical ID tag.

Bibliographic references:

  • Robinson, R. (2002). Anaphylaxis. In D. S. Blanchfield & J. L. Longe (Eds.), The Gale Encyclopedia of Medicine (2nd ed., Vol. 1, pp. 178-180). Detroit: Gale.
  • MedlinePlus (2018). Anaphylaxis. Available at [Accessed 06 June 2018].
  • .