Fighting food allergies among schoolchildren
As children start the new school term, concerns over the threat of food allergies might prey on the minds of many parents.
Food allergies are among the most common type of allergic disorder, with between 6 and 8 per cent of children up to the age of 3 having a food allergy across Europe and North America.
One in every 20 children will develop a food allergy, which means that every primary school year group is likely to have a child with an allergy.
They can cause severe reactions, which in some cases are even deadly, and research shows there has been a 500 per cent increase in the rate of hospital admissions for children with food allergies in the UK.
However, diagnosis can be difficult, which has led to growing numbers of people incorrectly self-diagnosing themselves. NICE estimates that only between 25 and 40 per cent of self-reported food allergies are clinically confirmed as true.
And there are concerns that children are being diagnosed by their parents as having a food allergy when in fact they have a food intolerance, or even just a stomach complaint.
NICE produced a clinical guideline on food allergies in February 2011, which covers the diagnosis and assessment of the condition among children and young people.
It contains recommendations on when it is appropriate to test a child or young person for a food allergy, and what kind of tests should be used for diagnosis.
Mandy East, National Coordinator at the Allergy Strategy Group, thinks it would be helpful for parents, teachers and primary care staff to be aware of the recommendations in the NICE guideline.
She says: "It is sensible for parents who have any concerns about food allergy to read the Understanding NICE Guidance (UNG) version of the guideline to understand the symptoms of food allergy and to visit their family doctor.
"Teachers, with their duty of care for children, may also like to be aware of the signs and symptoms of allergy and be aware of the NICE guidelines.
"If a child starts to feel unwell under their care, it is their duty to tell the parent.
"But a lot more needs to be done and there also needs to be greater awareness in primary care.
"The NICE guideline has gone a long way to do that, but we still have to work hard to educate GPs and their primary care colleagues to ensure the information included is acted upon."
Dispelling myths and raising awareness
A lack of general awareness over symptoms can be seen in the high numbers of people incorrectly self-diagnosing themselves, with rates of occurrence overestimated by up to four times.
Furthermore, an estimated 20 per cent of children who report having an allergy are actually wrongly self-reporting diagnoses of various food allergies.
Some even avoid eating particular foods because they mistakenly believe they are allergic to them.
Ms East thinks that while misdiagnosis is rife, it is important to be aware of any symptoms children may exhibit.
She says: “A number of adults do wrongly self-diagnose themselves as having a food allergy.
"So parents and members of the public should make themselves aware of the NICE guideline so that they can recognise any signs or symptoms.
"But it is more likely that adults will misdiagnose themselves than children, as children are unlikely to make up symptoms.
"The worry is that due to lack of awareness, parents might misinterpret the symptoms of food allergies that would otherwise be picked up.
"It is also important that tests are taken to rule out the possibility of food allergies being present - as symptoms might indicate other underlying problems.”
Recognise symptoms by reading NICE guidelines
Food allergy can be classified into IgE (immunoglobulin)-mediated and non-IgE-mediated allergy.
The NICE guidelines identify two types of food allergy and provide details on the possible symptoms associated with each of them.
The allergies are categorised by whether they are triggered by an antibody called immunoglobulin E (IgE).
Common reactions to IgE-mediated food allergies tend to happen very quickly after eating a particular food.
These include a reddening of the skin, an itchy rash and swelling of the lips, face or around the eyes.
Food allergies not triggered by IgE are usually caused by cell reactions in the immune system.
These reactions do not occur immediately, and often take several hours or days to appear after the food is eaten.
Symptoms include eczema, diarrhoea, constipation and growth problems in severe cases.
It is only if this kind of food allergy is suspected that there should be supervised elimination of the suspected food for a specific period (usually between 2 and 6 weeks), before reintroducing it.
NICE recommends that healthcare professionals should provide advice before a child is started on a diet to eliminate certain kinds of food.
This should include information on how to understand food labeling and to ensure that children do not eat the suspected food unintentionally.
Ms East says: "Parents who are worried that their child might have an allergic disorder should visit their family doctor in the first instance, where a full allergy-focused history should be taken along with tests to diagnose the condition if relevant."
An anaphylactic reaction is a rare but serious reaction that can occur in this type of food allergies. Signs of anaphylaxis may include breathing difficulties, dizziness, itchy skin or a raised red skin rash and swelling of lips, hands or feet.
Some tests are better than others
The guideline recommends two tests for diagnosing food allergies.
If a healthcare professional suspects that the child has IgE-mediated food allergy, then a skin prick test and/or a blood test should be used for diagnosis. This should be based on the results of an allergy-focussed clinical history.
A skin prick test involves putting a small drop of liquid that has a suspected food protein on the forearm. The skin is then pricked through the drop to see if a reaction occurs.
The doctor or practice nurse will decide which test to give based on the results of an allergy-focussed medical history, and on how safe and acceptable the test is to the child.
Ms East says: "According to the NICE guidelines, the family doctor should take a full clinical history before proceeding with taking a test.
"It's not just a case of taking a test for an allergy once there are some symptoms.
"A family doctor can carry out a blood test. This is a simple test where blood is sent away for testing at a local lab. The results will be returned to the doctor for discussion at a follow-up appointment.
"Skin prick testing is more likely to be carried out in a hospital setting.
"However, both tests recommended by the NICE guidelines are equally efficacious."
The guideline also advises against using alternative tests for food allergies, such as hair analysis, applied kinesiology, vega tests and serum-specific IgG antibody tests.
Some of these tests are commercially available and have risen in popularity in recent years.
Ms East agrees with NICE's recommendations which state that healthcare professionals should not offer these tests, as there is no evidence that they can reliably diagnose food allergy.
She says: "People should avoid alternative tests, as the skin prick test and the blood test recommended in the NICE guideline are the only ones proven to be effective.
"Alternative tests do not work, and some even advise you to avoid certain kinds of food unnecessarily."
20 September 2011