Anaphylactic Shock

Causes of anaphylaxis

This extreme allergic reaction has an intense effect on the body, causing a sudden drop in blood pressure and narrowing of the airways that can be fatal. Anaphylactic shock can be caused by anything, but among the most common triggers are: nuts (for those who are particularly sensitive, even touching the trace of a nut can be potentially fatal), seafood, insect stings and bites, and drugs (some people have a very extreme reaction to penicillin, for example).

As with asthma, the number of people suffering allergic reactions appears to be increasing. Whether this is because people are becoming more sensitive to allergens (the substances that cause allergic reactions) or whether we are just becoming better at detecting allergies, nobody is really sure.

Signs and symptoms

One of the main effects of severe anaphylaxis is a constriction of the air passages in a similar way to asthma but generally more severe, preventing the intake of any oxygen at all. There may be a history of contact with a particular allergen, the thing that triggers the attack. Anaphylaxis can happen very quickly, within seconds.

Signs and symptoms includes:

• Difficulty breathing
• Pale skin and blue lips
• Blotches on the skin
• Rapid pulse
• Breathing and heartbeat stopping

Treatment

1. Call an ambulance immediately. The casualty needs adrenaline to counteract the reaction.
2. If the casualty is a known sufferer she may have an adrenaline injection. Help her to administer this. If you have been trained and the casualty is unable to do so, you may give the injection.
3. Place the casualty in the most comfortable position and reassure her.
4. If the casualty becomes unconscious, place in the recovery position.

Monitor the casualty's breathing and circulation and be prepared to resuscitate if necessary.

Skin prick test for allergies

Skin prick tests are simple procedures carried out to find out what substances (allergens) cause allergic reactions in an affected person. Extracts of allergens that commonly cause allergic reactions, such as food, pollen and dust are made into dilute solutions and are then placed on the skin. The skin is pierced to allow the substance to be absorbed.

1. Dilute solutions of substances that a person is thought to be allergic to are placed on the skin, usually the arm, and the skin is then pricked with a needle. Several different allergens can be tested on the skin at the same time.
2. An allergic reaction usually takes place within 30 minutes of the test. lf the person is allergic to the substance a red weal, indicating a positive reaction, appears at the site where the needle pricked the skin.

Handling an attack

Many anaphylaxis sufferers carry an auto-injector with a measured dose of a known treatment for an attack, most commonly adrenaline. This will often look like a pen. It is easily administered by placing against the skin and clicking the end. Help the person having the attack, to find and inject the medication.