Anaphylaxis is a severe life threatening allergic reaction that involves two or more body systems. Anaphylaxis literally means "without protection". When a severe allergic reaction occurs, the body's defence mechanisms fail. This leads to the involvement of many organs such as the lungs, heart, brain, skin, gut, etc. The outcome for anaphylaxis is life or death. Hence recognition of symptoms, and taking immediate action are of paramount importance.

The reaction may occur in three phases:

• initial phase
• late phase about 6 to 8 hours later, and
• protracted phase up to 32 hours later.

The cofactors for anaphylaxis include:

• asthma
• use of beta blockers, ACE inhibitors or NSAIDS
• use of opiod drugs and muscle relaxants
• food allergy

This means that a person who has asthma or food allergies is at a higher risk for an anaphylactic reaction.

Symptoms
The symptoms of anaphylaxis include:

• hives
• tingling in mouth
• flushed face or body
• swelling (eyes, lips, face, tongue)
• tightness (throat, mouth, chest)
• metallic taste in mouth
• difficulty breathing or swallowing
• coughing, choking or wheezing
• change of voice
• change of skin colour
• vomiting, stomach cramps, diarrhea
• incontinence
• dizziness, unsteadiness
• feeling of fear or foreboding
• fainting or loss of consciousness
• cold, clammy, sweaty skin
• confusion, seizures, light-headedness

Some of the common causes of anaphylaxis include:

• food
• latex
• insect stings
• exercise
• medication

Some foods that commonly cause anaphylaxis are:

• peanuts
• nuts
• milk
• eggs
• wheat
• corn
• beef
• pork
• fish
• shellfish
• chocolate
• soy
• food additives

Peanuts are not a nut but belong to the legume family that includes lentils and soy.

Note that none of these lists is complete. A person can be anaphylactic to almost any thing. If you suspect anaphylaxis, begin treatment as described below.

Treating Anaphylaxis
1. Immediately, use an epinephrine injector (such as the EpiPen or Twinject).
2. Obtain professional emergency medical assistance.

Using the EpiPen
1. Remove the grey cap from the flat end.
2. Position the rounded black end against outer thigh.
3. Press firmly till you hear a Click!
4. Hold for 10 seconds, then remove.
5. Phone for medical assistance (911).

Using the Twinject
1. Remove both the green and red cap.
2. Position the grey end against outer thigh.
3. Press firmly.
4. Hold for 10 seconds, then remove.
5. Check if needle is exposed which indicates that the dose was received.
6. Phone for medical assistance (911).

When to use epinephrine:

• when symptoms are severe
• when in doubt

Golden rule for treatment of anaphylaxis
If in doubt, DO:

• use the epinephrine injector (or EpiPen)
• obtain professional medical assistance

Keep the person lying down with legs supported so that the feet are higher than the head. Do not allow the person to stand up. Respiratory arrest can occur in 10 - 30 minutes in persons who are standing after an anaphylactic reaction. A sudden change to an upright posture can result in sudden death.

Epinephrine given early can save lives. Too often it is the delay in giving epinephrine that results in death. Speed is of the essence. Because there can be late or protracted reaction, every person who has an anaphylactic reaction (one that involves two or more body systems) must be sent to hospital for further observation and if necessary, treatment.

Once in hospital, adjunct treatment may include fluid therapy, H1 and H2 histamine receptor antagonists, corticosteroids and bronchodilatros. In all cases, every person who has an anaphylactic reaction must be observed closely and be under medical supervision to ensure that there is no delayed or late phase reaction which can be more severe than the initial reaction.

To download a free patient education sheet on anaphylaxis, click here.