The number of Australian children being hospitalised with potentially fatal food allergies is increasing, new research has found.
A study of hospital admissions from 2005 to 2013 found a 50 per cent jump in children with anaphylaxis, potentially life-threatening allergic reactions.
Murdoch Childrens Research Institute’s (MCRI) Professor Mimi Tang said the highest rates of hospital admissions were in younger children, but there was a 110 per cent increase in rates in older children (aged 5 – 14).
“What we think is happening is that more children are getting food allergies but of concern, these allergies tend to be peanut, tree nut and shellfish that you don’t grow out of,” she said.
Researchers said they were not sure if the cases are newly diagnosed children with food allergies, or whether children were just suffering more serious attacks, meaning they ended up in hospital.
“Allergic reactions in older children tend to be more severe, meaning they can end up in hospital,” Professor Tang said.
Anaphylaxis is the most severe form of allergic reaction and is potentially life-threatening.
It must be treated as a medical emergency, requiring immediate treatment and urgent medical attention.
Anaphylaxis is a generalised allergic reaction, which often involves more than one body system (for example skin, respiratory, gastro-intestinal and cardiovascular).
Doctors from the Australasian Society for Clinical Immunology and Allergy said a severe allergic reaction or anaphylaxis usually occurred within 20 minutes to two hours of exposure to the trigger and could rapidly become fatal.
While the explanation underlying the increase in food allergies remains uncertain, experts said certain risk factors were starting to emerge.
“These might include exposure to environmental risk factors, perhaps causing inheritable epigenetic changes by activating or silencing genes important to immune regulation,” said lead author, Dr Raymond Mullins from the University of Canberra.
The so-called hygiene hypothesis could be a factor.
Dr James Li from the Mayo Clinic in the US said the hygiene hypothesis proposes that childhood exposure to germs and certain infections helped the immune system develop.
“This teaches the body to differentiate harmless substances from the harmful substances that trigger asthma,” he said.
“In theory, exposure to certain germs teaches the immune system not to overreact.”
Experts said this new research showed that childhood food allergies were continuing to increase and the burden was now shifting to teenagers and older children.
Food allergies impacting on people’s lives
When she was five, Caitlin Louey had a reaction to eating food topped with peanuts, with vomiting and feeling sick.
After tests at the Murdoch Childrens Research Institute, she found she was allergic to several nuts.
“I just have to monitor what I eat and when I am eating out, I make sure that my friends know what I can eat,” the now 16-year-old said.
She said it was not until she took part in the MCRI’s SchoolNuts study that she found she had an anaphylactic reaction to pecan nuts, peanut and walnut.
“Luckily, I was in a hospital setting and started to feel shortness of breath. They gave me the adrenalin treatment and I felt fine,” she said.
“Having a food allergy is something so many people have to deal with and it can be life threatening, so I think it’s important for the general public and the community to be fully aware of the severity of food allergy and the impact on people’s lives.”
If an allergy is suspected doctors may do a series of allergy tests, usually a blood test for allergen specific IgE (formerly known as RAST tests) or skin prick testing, to help confirm or exclude potential triggers.
The Australasian Society for Clinical Immunology and Allergy said some methods which claim to test for allergies (including cytotoxic food testing, Vega testing, kinesiology, allergy elimination techniques, iridology, pulse testing, Alcat testing, Rinkel’s intradermal testing, reflexology, hair analysis and IgG food allergy testing) were not medically or scientifically proven methods to confirm allergy.
Food allergy facts:
Anaphylaxis is a potentially life-threatening, severe allergic reaction and should always be treated as a medical emergency.
Symptoms can include:
- Difficult/noisy breathing
- Swelling of tongue
- Swelling/tightness in throat
- Difficulty talking and/or hoarse voice
- Wheeze or persistent cough
- Persistent dizziness and/or collapse
- Pale and floppy (in young children)
In some cases, anaphylaxis is preceded by less dangerous allergic symptoms such as:
- Swelling of face, lips and/or eyes
- Hives or welts
- Abdominal pain, vomiting (these are signs of anaphylaxis for insect allergy)