Food sensitivities have never been more common, and the effects are obvious everywhere from our kids' lunchboxes to restaurant menus. But what's behind this increase? In a special report, Chrissie Russell asks the experts for the most up-to-date advice, meets the families coping with serious allergies and finds out what the future holds for those affected by the problem.
Perhaps you're a parent who has had a letter home from your child's school instructing you not to allow nuts into your son or daughter's lunchbox, or maybe you've learned not to serve your mother-in-law shellfish unless you want to make a quick dash to A&E.
Or you might just have personal experience of a lifetime spent asking waiting staff to return to the kitchen and (please, please) ask the chef if any of the dishes on the menu contain eggs. Whoever you are in Ireland today, the chances are you've encountered a food allergy.
Hypersensitivity to food is on the rise. It's now estimated that approximately 5pc of Irish children and 3pc of adults suffer from a food allergy. Twenty years ago, just 1pc of the population was affected. The level of severe reactions, requiring a trip to A&E, has also escalated.
"Rates of anaphylaxis attendance to hospital have also gone up - they have trebled in the last 20 years," reveals Professor Jonathan Hourihane, professor of paediatrics in UCC and principal investigator in the UCC's Infant Research Centre. "Death due to food allergy hasn't increased, because it's always rare, but food allergies are definitely more common these days."
So why are we seeing such an increase in allergic reactions? Interestingly, the highest rates of allergies are at the latitudes of the British Isles, Canada and New Zealand. "The nearer you get to the equator, the lower the rate of allergies," reveals Professor Hourihane. "That's shown in both Europe and the southern hemisphere. There's hardly any peanut allergy in Darwin in Australia but it's very common in Melbourne. It's very common in Ireland, but very unusual in Greece."
The evidence suggests that lower levels of vitamin D and less exposure to sunlight correlates with a higher incidence of allergies.
Another theory is the so called 'hygiene hypothesis' - the idea being that our improved levels of cleanliness and reduced exposure to germs has actually contributed to a decrease in tolerance, inducing dust and bacteria antigens. "But that doesn't explain everything," says Prof Hourihane. "No theory is going to explain everything."
Other studies have shown that children from larger families are less likely to develop allergies, babies born via C-section have higher risk of allergies, breastfed babies have lower risk of allergies, and studies in Finland revealed that those living close to green spaces and agriculture rather than close to a town where less likely to suffer from food allergies.
"But the biggest issue is that in the last two or three years we've revolutionised our advice about weaning," reveals Prof Hourihane. On the basis of scientific studies published in 2015 and 2016, the old advice to avoid allergens - like nuts or shellfish - when pregnant or weaning has been flipped on its head.
Now the advice is to introduce those foods as early as possible and expose the infant to those foods to create a tolerance. It's avoiding the 'danger' foods that is more likely to create an allergy. Firms in America are being granted permission to label peanut butter as healthy for babies with the advice to introduce it early and regularly to their diet.
The difficulty lies in dispelling popular myths around food allergies.
"Unfortunately everyone's got an opinion on food and the minute someone gets bloated or gets a headache or a rash, then there's someone ready to say 'oh it must be something you ate'," says Prof Hourihane.
"Seventy per cent of children that come into my clinic go out the door with more foods in their diet than less. They're usually on over-restricted diets because someone has said 'you'd better stay off that just in case' when actually, we want you to eat everything and then we'll tell you what to avoid properly when you come to see us."
"Basically, if you're eating something and not reacting then keep eating it, don't avoid or eliminate it," agrees paediatric dietitian Ruth Charles.
For example, it might feel the natural response for a parent to remove tomatoes from a child's diet if they think they're causing a rash but it's key to seek a professional opinion.
"It's all about assessing and managing risk, that's why a qualified clinician is needed to diagnose perceived from true food allergy," explains Charles, who founded the Irish Food Allergy Network.
"A rash as the only symptom is considered a 'mild' reaction and is probably due to skin contact with the natural acids and histamine in the tomato. If the child in this case continues to eat tomato, gets a rash each time but it otherwise happy and well with no other symptoms, and likes tomato, then keep giving it."
"The big things are children who are upset and difficult feeders or who have eczema in the first year of life and the woman at the bus stop will say 'well maybe you should take milk or egg or wheat out of your diet'," continues Prof Hourihane.
"Well, that would be OK it the woman at the bus stop was a State-registered dietitian who could supervise those exclusions, but she's not. Eczema always pre-exists before a food allergy comes along, so changing your diet to fix your eczema will probably work for one child I see out of 2,000."
Across the board there's a greater need for understanding and awareness. In 2015, then-health minister Leo Varadkar signed new laws allowing trained members of the public to administer life-saving medications, including adrenaline. Colleges, workplaces and sports venues are permitted to hold AAIs (adrenaline auto-injectors), yet many remain oblivious to this legislation.
"In Ireland specifically, there is a need for training and the establishment of guidelines for all those caring for children in the community - teachers, creche workers, sports coaches - in the management of food allergy and to ensure safety and, at the same time, inclusion for allergic children," says Dr Aideen Byrne, clinical lead for allergy at Our Lady's Children's Hospital (OLCHC) and the National Children's Hospital, Tallaght.
There's also an urgent need for greater provision of resources to manage Ireland's soaring rate of allergies.
"At present, OLCHC has one consultant allergist, and this post is divided between OLCHC and the National Children's Hospital, Tallaght," explains Dr Byrne. "A business case for an additional consultant post has been submitted to the HSE as part of the 2018 Service Plan."
Typically, a patient referred to Professor Hourihane has to wait 10 months. "It's terrible and the pressure is building up all the time," he says. "I'd love to see access within a week but we can't do that because I get 80 referrals a month.
"We want to try and improve the amount of knowledge and access in other parts of the country, and we're trying to develop a syllabus for trainees in Irish Paediatrics so that by the time they finish their training, at least they've heard something about food allergy."
He adds: "I think food allergy is a common primary care in the community disease, but there's no expertise out there and instead patients have to come and see a professor and a consultant to do perfectly simple things and by the time families get to see me, they're up to ninety."