Symptoms of extreme allergic reactions explained

ALLERGIES can happen to anyone at any time, even if there’s no known family history of such problems. 

An increasing number of people are suffering from severe — potentially life-threatening — reactions.

SERIOUS CONCERN: Like all reactions, anaphylaxis can occur out of the blue — and it’s a medical emergency, causing severe breathing difficulties, a drop in blood pressure and swelling of the face and airways.

Allergies can develop at any age.

Adult-onset allergy can mean adults who’ve eaten a food all their life, for example, can suddenly develop an allergy, and it can be a severe anyphylactic reaction.

NEED TO KNOW: The main symptoms may occur alongside milder reactions, such as a red, raised and itchy rash, and while a reaction is usually classed as anaphylactic when the lungs, heart rhythm or blood pressure are affected, there may be other signs.

For example, if someone starts vomiting after an insect sting, it can be the first indicator of anaphylaxis, because the sting has led to the release of chemicals which have travelled to the gut, and the vomiting may herald a more severe reaction.

In general, anaphylaxis is an immediate reaction, with symptoms developing within minutes, or certainly within half an hour of being exposed to the allergen.

Antihistamines are usually effective for most milder allergic reactions but take too long to work when someone’s having an anaphylactic attack — which should always be treated urgently with adrenaline, usually injected into the upper-outer thigh with an auto-injector adrenaline pen prescribed by a doctor (people known to be at risk of anaphylaxis are generally advised to carry one on them at all times).

An ambulance should be called — even if an adrenaline injection has been given — and the person who’s had the anaphylactic reaction should lie down, to help maintain blood pressure.

Deaths from anaphylaxis are extremely rare, and tend to be when medication is given too late or isn’t available at all. In the majority of cases, adrenaline starts to work on the system straight away.

WHAT’S GOING ON? In most allergic reactions, allergens in the offending substance lead to the release of chemicals — like histamine — into the tissues in a particular part of the body, like the skin or eyes.

As a result, symptoms, such as a skin rash, or red, itchy eyes, are usually seen in this area.

But in anaphylaxis, the chemicals are released into the bloodstream, causing serious symptoms very quickly.

Anaphylaxis is slightly more likely in people who’ve had a previous anaphylactic reaction, moderate, severe or uncontrolled asthma, a reaction after only skin contact with an allergen, or in people who have cardiovascular disease.

SPOT THE SIGNS: Typical symptoms are:

• Swelling of the tongue and/or throat.
• Difficulty swallowing or speaking.
• Vocal changes (hoarse voice).
• Wheeze, a persistent cough or severe asthma.
• Difficult or noisy breathing.
• Stomach cramps or vomiting after an insect sting.
• Dizziness, collapse, loss of consciousness.
• A sense of impending doom.

See www.irishanaphylaxis.org