The Anaphylactic Shock in Children Food Allergy
An anaphylactic reaction may occur to a very sensitive allergic person when exposed to the allergen. The anaphylactic reaction, or anaphylaxis, is a severe and sudden allergic reaction that involves the whole body: the allergen binds to the allergic antibodies, the IgE, that activates mast cells (a particular type of immune system cells) to suddenly release large quantities of immunological substances that, by cascade, activate a very strong and life threatening immune reaction called the anaphylaxis shock. If untreated, anaphylactic shock can quickly lead to death.
Anaphylaxis can occur in response to food allergies: milk, eggs, peanuts, wheat, soy, fish, shellfish and tree nuts are the foods that most often cause anaphylaxis in people who are allergic to these foods. Other types of allergens triggering anaphylaxis are insect bites, stings or drugs, while inhaled allergens such as pollens are rarely related to anaphylaxis.
Symptoms of anaphylaxis are those typical of an allergic reaction such as abdominal pain, bloating, vomiting, diarrhea, itchy skin, and swelling of the skin during hives. In addition, when an anaphylactic shock occurs there is an enlargement of the small blood vessels (vasodilatation) which lowens the blood pressure of the body and causes fluid to leak from the bloodstream into the tissues, causing oedema. Moreover, allergic substances force a sudden contraction of the muscles that are part of the lung walls, the bronchioles (bronchospasm, the constriction of the airways) resulting in a difficulty to breathe.
The time between the ingestion of the allergen and the appearance of anaphylaxis symptoms can vary: they can appear immediately but also can be delayed by half an hour to several hours. Reaction time and intensity can be different according to each individual and depends on the amount of allergen ingested. However, symptoms of anaphylactic shock usually appear very quickly once they do begin.
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