Saturday 22 July 2017

Allaying allergies

If you suspect that your child has an allergy that is affecting their quality of life, you should seek out medical advice to get to the root of the matter, writes Deirdre Nolan

Deirdre Nolan

RED, itchy eyes; blocked nose; sneezing; coughing; hives … sound familiar? These are the classic, telltale signs of an allergic reaction. It's believed that a quarter of Irish children have some type of allergy, which can manifest in diseases such as rhinitis, sinusitis, asthma, dermatitis, eczema and hayfever.

As many of the symptoms of allergy are also associated with the common cold, it can be difficult to diagnose. The duration of the symptoms, however, can indicate an allergy.

"If you have a child who has unresolved symptoms, particularly if they're interfering with quality of life, and you've not been able to get a handle on it, then you should be talking to somebody who knows about allergy," says Joe FitzGibbon, a medical doctor with specialist interests in allergy, fatigue, and nutrition, and the author of Could it be an allergy?

" The most common allergies in young children in terms of food would be cow's milk and egg white. With air-borne allergens, things like house-dust mites, pollens and cat allergies would be common, and followed by horse and dog allergies," he explains.

It is easy to become confused between allergy and intolerance, but there is a medical difference.

" When doctors talk about allergy they are referring to a very specific mechanism in the immune system that involves the immunoglobulin we call IgE. The IgE molecules are programmed specifically to recognise one allergen. It sparks off a cascade of events in the immune system, which lead to very predictable and reproducible symptoms. They are the symptoms of histamine release in the body."

An allergy can be reliably, quickly and easily detected by a skin-prick test, which can be used to test many allergens at the same time.

"An intolerance is any sort of reaction other than IgE. Intolerance isn't more easily cured than an allergy and invariably relates to foods. In the intolerance group you have some forms that are immunemediated, others that are not. Non-immune-mediated intolerance would be, for example, lactose intolerance, where drinking milk causes diarrhoea, bloating and abdominal discomfort. It's due to an enzyme deficiency in the gut, which cannot break down the milk sugar lactose," says FitzGibbon.

"An example of an immune-mediated intolerance would be coeliac disease, where you have gluten intolerance. That's where the immune system reacts very badly to gluten, but it does not involve the IgE cascade. It's a different department within the immune system that's activated."

The most serious type of allergic reaction is called anaphylaxis, which, if left untreated, can cause death. Anaphylaxis should always be treated as a medical emergency and patients should be rushed to hospital if an anaphylactic event occurs.

"Anaphylaxis is a very real problem for a very small minority of people. What makes an allergy life threatening is ABC. A is for your airway – if you're trying to breathe and you can't get the air in. If the larynx is swollen then your airway is threatened. B is for breathing – if you have bronchospasm or sudden severe asthma. C is for cardiac collapse, when the patient becomes unconscious," FitzGibbon explains. " The ABC is how we would define severe allergic reaction. If somebody has a diagnosis of anaphylaxis made following such an episode, you have to do everything you possibly can to identify the causative agent."

Mother & Babies

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