Anaphylaxis (anaphylaxis): symptoms, causes and treatment

Anaphylaxis is an allergic reaction caused by different allergens such as drugs, food or insect bites, among others. It can be potentially fatal if not treated immediately.

We will explain below what is anaphylaxis or anaphylaxis, What are its most common causes, what symptoms does it cause, how is the diagnosis made, what treatment is applied to alleviate its symptoms, what is the prognosis to which it can lead and what preventive measures can be taken to avoid it.

    Anaphylaxis (anaphylaxis): what is it?

    Anaphylaxis is an allergic reaction that progresses rapidly and endangers the patient’s life. The immune system reacts to substances that would otherwise be harmless to the environment (allergens).

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

      common causes

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

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

      • Fish, seafood and shellfish.
      • Nuts and seeds.
      • Bee, wasps or wasps stings.
      • Papaya meat marinades.
      • Vaccines, including influenza and measles vaccines.
      • Penicillin.
      • Cephalosporins.
      • Streptomycin.
      • gamma globulin.
      • Insulin.
      • Hormones (ACTH, thyroid stimulating hormone).
      • Aspirin and other NSAIDs.
      • Latex, examination gloves or condoms, for example.

      Additionally, exposure to cold or exercise can trigger an anaphylactic response in some people.

      Symptoms of anaphylaxis

      Symptoms develop quickly, usually within seconds or minutes. Anaphylaxis can include any of the following symptoms listed below. However, not everyone is required to attend.

      • abdominal pain.
      • Anxiety and / or confusion.
      • Discomfort or feeling of tightness in the chest.
      • Diarrhea.
      • ramps.
      • Wheezing.
      • Difficulty in breathing, Cough, wheezing, or high-pitched breathing noise.
      • Difficulty swallowing.
      • Stunned.
      • Hives, itching, redness of the skin.
      • Nasal congestion.
      • Nausea and vomiting.
      • Palpitations.
      • Poor articulation of language.
      • Swelling of the face and eyes.
      • Swelling and irritation of the tongue and / or mouth.
      • Swelling of the breasts.
      • Loss of consciousness.


      Anaphylactic reaction is diagnosed based on the rapid development of symptoms in response to a suspected allergen. Its identification can be done with the RAST test. This is a blood test that identifies reactions of IgE (immunoglobulin type E) to specific allergens. Skin tests may be done for milder anaphylactic reactions.


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

      Antihistamines can be used for rashes and aminophylline for bronchial constriction. If the upper airway is obstructed, it may be necessary to place a breathing tube or a tracheostomy tube.

      Forecasts and expectations

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

      How quickly symptoms develop is an indication of the possible severity of the reaction: the faster the symptoms develop, the more severe the final reaction. Going to and seeing a doctor urgently reduces the risk of death from anaphylaxis. This is why most people get prompt treatment they completely recover.

      If left untreated, anaphylaxis can block the airways. cause cardiac arrest, respiratory arrest, or fatal anaphylactic shock.

      Prevention: what can we do to prevent it?

      The main reliable way to prevent anaphylaxis and allergic reactions is to avoid allergic triggers, such as foods and drugs, which have caused an allergic reaction in the past.

      For insect allergies, this requires recognition of likely nesting sites. Prevention of food allergies requires knowledge of prepared foods or dishes in which the allergen is likely to occur, and a careful questioning of the ingredients in the restaurant.

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

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

      Bibliographical references:

      • Robinson, R. (2002). Anaphylaxis. In DS Blanchfield and JL Longe (Eds.), The Gale Encyclopedia of Medicine (2nd ed., Vol. 1, pp. 178-180). Detroit: Gale.
      • MedlinePlus (2018). Anaphylaxis. Available at [Consultado 06 junio 2018].

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