Basic facts

What is anaphylaxis?

Anaphylaxis is an extreme and severe allergic reaction. The whole body is affected, often within minutes of exposure to the allergen but sometimes after hours.

A short film was created to coincide with the launch of new guidelines on the management of Adult Anaphylaxis by the Royal College of Physicians click here to find out more about anaphylaxis and the work of The Anaphylaxis Campaign.

What can cause anaphylaxis?

Common causes include foods such as peanuts, tree nuts (e.g. almonds, walnuts, cashews, Brazils), sesame, fish, shellfish, dairy products and eggs. Non-food causes include wasp or bee stings, natural latex (rubber), penicillin or any other drug or injection. In some people, exercise can trigger a severe reaction - either on its own or in combination with other factors such as food or drugs (e.g. aspirin).

What are the symptoms?

• generalised flushing of the skin

• nettle rash (hives) anywhere on the body

• sense of impending doom

• swelling of throat and mouth

• difficulty in swallowing or speaking

• alterations in heart rate

• severe asthma

• abdominal pain, nausea and vomiting

• sudden feeling of weakness (drop in blood pressure)

• collapse and unconsciousness

Nobody would necessarily experience all of these symptoms.

Why does anaphylaxis occur?

Any allergic reaction, including the most extreme form, anaphylactic shock, occurs because the body's immune system reacts inappropriately in response to the presence of a substance that 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 antibody (IgE) and the substance (allergen) causing the anaphylactic reaction. This mechanism is so sensitive that minute quantities of the allergen can cause a reaction. The released chemicals act on blood vessels to cause the swelling in the mouth and anywhere on the skin. There is a fall in blood pressure and, in asthmatics, the effect is mainly on the lungs.

What is the treatment for a severe reaction?

Pre-loaded adrenaline injection kits are available on prescription for those believed to be at risk. Adrenaline (also known as 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.

Am I at risk from anaphylaxis?

If you have suffered a bad allergic reaction in the past – whatever the cause – then any future reaction is also likely to be severe. If you have suffered a significant reaction to a tiny dose, or have reacted on skin contact, this might also be a sign that a larger dose may trigger a severe reaction. If you have asthma as well as allergies, getting seen by an allergy specialist is particularly important because asthma can put you in a higher risk category. Where foods such as nuts, seeds, shellfish and fish are concerned, even mild symptoms should not be ignored because future reactions may be severe.

What allergy patients should expect from the NHS

To download this advice click here

• When presenting to the local surgery, with symptoms for the first time, the allergy patient should expect to see a doctor or nurse trained in the diagnosis and management of allergy

• The allergy patient should expect their doctor to be well versed on the practicalities of making a referral

• A quick referral is required by those patients whose allergies are complex, severe and potentially life threatening

• The GP should be trained well enough to make this decision

• Each child should be referred to a consultant paediatric allergist so that all issues relating to their health can be considered

• All patients should have access to a full allergy service and dedicated allergy teams

• All allergy patients need allergy care based on a personalised allergy plan which supports the day-to-day control and management of their condition

• In order to have an individual management plan, the health service needs to ensure adequate time is set aside for full discussion of symptoms, treatment, appropriate medication and trigger avoidance

• To avoid an overload of information on diagnosis, a series of appointments is appropriate

• All patients at risk of life-threatening allergies need to know that during any emergency, those responsible for their care are following locally agreed, standard emergency management protocols

• After any severe reaction every patient needs to be referred to a specialist in allergy irrespective of whether they have seen a consultant in the past

• Every patient suspected to be at risk of severe allergy should have at least one visit to a local, consultant allergist who provides a dedicated allergy service

If you feel you have not received adequate care and would like further information, please contact Mandy East on 01252 893850 mandy@anaphylaxis.org.uk