Anaphylaxis - what is it and what is going on ?

Common causes of anaphylactic shock
What are the symptoms
What is the treatment

Any allergic reaction, including the most extreme form, anaphylactic shock, occurs because the body's immune system over-reacts in response to the presence of a foreign body, which it wrongly perceives as a threat.

An anaphylactic reaction is caused by the sudden release of chemical substances, including histamine, from cells in the blood and tissues where they are stored. The release is triggered by the reaction between the allergic sort of antibodies (IgE) with the foreign body (allergen) causing the anaphylactic reaction. The mechanism is so sensitive that unbelievably small quantities of the allergen can cause a reaction. The released chemicals act on blood vessels to cause the swelling and low blood pressure, and on the lungs to cause asthma.
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What are the most common causes of anaphylactic shock ?

The most common causes of anaphylactic shock are: nuts;in particular peanuts, fish ( especially shellfish ), sesame seeds, dairy products, eggs, soya, wasp or bee stings, natural latex (rubber), penicillin and other drugs. Severe allergic reactions to fresh fruit (including kiwis and apples) are also increasingly being reported. In some individuals, exercise can trigger a reaction - either on its own, or in combination with other factors such as ingestion of a particular food.
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What are the symptoms ?

Typical symptoms are:

¡¤ swelling of throat and mouth
¡¤ difficulty in swallowing or speaking
¡¤ alterations in heart rate
¡¤ difficulty breathing - due to severe asthma or throat swelling
¡¤ hives anywhere on the body, especially large hives
¡¤ generalised flushing of the skin
¡¤ abdominal cramps, nausea and vomiting
¡¤ sudden feeling of weakness (drop in blood pressure)
¡¤ sense of impending doom
¡¤ collapse and unconsciousness

Nobody would necessarily experience all of these symptoms. Some people find that the symptoms they experience are always mild. For example, there may be a tingling or itching in the mouth - nothing more. This may not be serious in itself. Nevertheless, it is wise in all cases to make an appointment with your GP and discuss with them whether it would be appropriate to refer you on to an allergy specialist. In particular, if you experience a marked difficulty in breathing or swallowing, and / or a sudden weakness or floppiness, these should be regarded as serious.
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What is the treatment and why does it work ?

In anaphylactic shock, blood vessels leak, bronchial tissues swell and blood pressure drops, causing choking and collapse. An anaphylactic reaction can be reversed through an injection of adrenaline ( also named epinephrine ).

Adrenaline (epinephrine) acts quickly to constrict blood vessels, relax smooth muscles in the lungs to improve breathing, stimulate the heartbeat and help to stop swelling around the face and lips (angioedema).

Accordingly when a serious reaction is suspected, the normal prescribed medical treatment is for an immediate injection of adrenaline to be given. If there is no improvement in five minutes, a second injection would then be given. In all cases of a serious reaction, an ambulance should be called and the person should be taken to hospital for further medical treatment and observation. This is important, because it is possible for the reaction to re-occur some time later.
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The information in this site should not be considered in any way whatsoever as medical advice or opinion. Readers must consult with their own doctor to deal directly with their specific circumstances. Products mentioned are not endorsed and are referred to solely as a matter of convenience to the reader.

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