Allergy Academy Study Day – Allergy for non-healthcare professionals

 

This was the first Allergy Academy study designed for non-healthcare professionals – more specifically for parents, families, teachers, nurses and carers working with allergy and, in particular, with allergic children. It covered the three main stages of the 'allergic march' – eczema, food allergy and asthma/respiratory allergy.

The food allergy presentations are below, please see here for the rhinitis presentation, here for the eczema presentation or here for a report on the full day.

Overview

The day was introduced by Dr Leanne Goh, a King's College Allergy Academy Fellow, who had also pulled the programme together.

Having traced allergy back to Mens, the first Pharoah of Egypt, who is thought to have died of an allergic reaction to a wasp sting, she emphasised the difference between immediate response and delayed response allergy, the former being relatively easy to diagnose, the latter, much harder. She also pointed out how infantile eczema frequently led to toddler/young child food allergy and then on to teenage asthma, hay fever and rhinitis – the allergic march.

Allergy is now the commonest childhood disease with up to 40% of children having asthma and one in seven having a nut allergy; this is the more concerning as their allergy impacts on every aspect of their lives.

But despite the fact that attending an allergy clinic significantly improves the general control and well being of an allergic child, the UK still falls far behind other European countries in their provision for allergy. In the UK there are around 15 dedicated allergists (as opposed to organ-based allergists) to care for a population of 60–70 million; in Germany (population 80 million) there are 50; in Denmark (population 2 million) there are 50 and in Finland (population 5 million) there are 100.

Dr Goh also quoted a study by Dr Richard Pumphrey which found that of the 48 allergy related fatalities that occurred between 1999 and 2006, not one had been assessed in an allergy clinic.

 

Adverse reactions to food
Dr Adam Fox, Consultant in Paediatric Allergy at St Thomas' Hospital and Director of the Allergy Academy.

Dr Fox also emphasised that the UK was the most allergic country in the world, although there had been a rapid and alarming growth in the incidence of allergy over the last ten years in South East Asia and South America, parts of the world which had been relatively allergy free.

He too emphasised the importance of distinguishing between immune related, immediate allergy and delayed response intolerance. The former is easy to diagnose as there is nothing else like it; the latter far harder as the symptoms are shared with many other conditions, there are no effective tests and there is no real understanding of the mechanisms.

He illustrated the difference by looking at cow's milk allergy which falls into three groups:

1. A very tiny amount of milk will cause a very speedy reaction. Blood tests will show an allergy. (In this case mast cells, triggered by the allergen, release histamine which causes the allergic reaction.)
2. A larger amount of milk (but not a huge amount) will trigger reactions such as an eczema flare up over 2–6 hours. Blood tests will show very little.
3. Cumulatively, a large volume of milk over several days will trigger reactions but all blood tests will be negative.

Moreover, reaction may depend on the processing of the allergen (the protein). For example, 80% of those who are allergic to raw egg can tolerate cooked egg.

Eczema and food allergy

There is a very important association between eczema in the first year of life and food allergy; this increases with the severity of the eczema (70% of infants with serious eczema will have a food allergy) and with the age that the eczema started (the younger, the higher the likelihood).

The symptoms of food allergy are very obvious: immediate (and reproducible) urticaria, hives, swelling, itchiness. However, fully blown anaphylaxis (a dramatic drop in blood pressure) is very rare in small children.

Common 'allergic' foods

The foods most frequently implicated tend to be directly related to the local diet so that in the UK and the West it is milk and eggs, in India it is gram flour, in Spain peach, in Indonesia, birds' nest.

Tests and diagnosis

Skinprick tests are not helpful for diagnosis as they give too many false positives (the child tests positive for an allergen to which they may be sensitised but to which they do not react), although they can be helpful for confirming a suspected allergy.

The gold standard for diagnosis of food allergy is a food challenge but this is expensive in doctor/nurse time – and the child will not always comply! Especially if he or she has had a bad reaction previously.

Quality of life

A diagnosis of food allergy can have a massive effect on the quality of life of both the child and its family – higher than a diagnosis of diabetes – as it brings with it concerns about nutrition, feeding behaviours and the possibility of a fatal reaction. However, families should remember that most fatalities occur in teenagers who also have badly controlled asthma and that the risk is still immensely much lower than the risk of dying in a car accident.

The aim is to get parents to be 'sensible' – to make a balanced risk assessment and to take reasonable precautions without becoming obsessive. But it is important that they are aware of the nutritional risks of restricting the diet; there is, for example, a marked increase in the the incidence of rickets amongst children attending allergy clinics as a result of vitamin deficiencies. It is therefore important to review the diet by challenge (but only under medical supervision) on a regular basis so as not to restrict it unnecessarily.

Finally, the New NICE guidelines, Food Allergy in Children and Young People, are very helpful.

 

Food Allergy in Practice
Tanya Wright, paediatric allergy dietitian, St Thomas' Hospital
(Also author of the excellent 'I'm Hungry... Easy family recipes free from milk, egg, soya, wheat & gluten'.)

Management of food allergy falls into four areas:

• What to know
• What to avoid
• How to avoid it
• How to replace it

What to know

Getting a diagnosis of food allergy is relatively easy; getting a diagnosis of hidden or delayed food sensitivity is more difficult.

• Keep a detailed food and symptom diary.
• Take any useful tests that may be available – but 'useful' tests do not include IgG tests which will not tell you anything useful.
• Exclusion and challenge (excluding the food for several weeks to see if symptoms improve then trying it again and seeing if symptoms worsen) is the only reliable way to diagnose a hidden food sensitivity.
• Once the problem food is identified it needs to be avoided – see below.
• Even if the food is avoided, there may still be symptoms. In which case a more detailed diary is needed. If possible a photo of the reaction and of the food/packaging of the food that is thought have caused the reaction is very helpful in diagnosis.

How much to avoid

It is important not to restrict unnecessarily so it is important to know whether the food needs to be avoided completely or just its consumption reduced. Similarly, whether the food can be eaten safely cooked (eggs or milk) but not raw. But this means that you need to know, for example, that cake icing uses raw egg whereas the cake itself uses cooked egg.

If the food needs to be avoided completely, then you need to be aware of contamination issues – the same utensil (knife, spoon, chopping board, drying up cloths) must not be used making egg/milk/nut-free food as for 'ordinary' food.

If the food needs to be avoided completely you also need to be aware of personal contact; if it is a small child no one who touches the child (parents, carers, friends, other children) must have touched the allergen as it can be easily transmitted to the allergic child.

Similarly, you will need to check vitamin pills and drugs and household cleaners for traces of allergen – Abicdec child vitamin pills, for example, contain refined peanut oil, Ecover washing up liquid includes a milk protein.

Finding safe foods

Shopping will become a lot tricker as every label needs to be checked.

• So many brands have both an allergen free and a non-allergen free version of the same product so you need to check which one you are buying viz: Birds custard, Heinz soups, Walkers Crisps.
• Products may have a totally unexpected allergen - a pea protein in chicken...
• Formulations of products may change to include an unexpected allergen without it being flagged up on the pack
Always double check the labels every time you shop.

Ensuring the allergic person still eats and tasty nutritious food

• Check up on standard products – they may already be allergen free and fine.
• Check labels on freefrom products to make sure that they are OK for you.
• Adapt family recipes to exclude the allergen.
• Try alternative grains, non-dairy milks, yogurts etc.
• Use apps such as FoodWiz to help you shop.
• Plan ahead, especially snacks.
• Bulk cook and freeze, but remember to label carefully.
• Use convenience foods wherever you can.
• Always have a contingency plan....

Getting the nutrition

Provided you are sensible, this will not be a problem. However, to be on the safe side you may wish to also supplement.

Communication

• It is very important that you tell everyone about your own or your child's allergy and how a reaction should be dealt with e.g. family, friends, teachers etc
• Apart from telling them about the allergy you can get jewelry, badges, lunch boxes, T-shirts and bibs all of which warn about the allergy.
• Translation cards are invaluable for travelling – but always take emergency supplies.

Medication

Carry your medication (Epipen) with you at all times. Up to 25% of those diagnosed with a potentially fatal allergy do not carry their emergency medication.

Reintroduction

Many food allergies, especially those in young children, resolve (they may become less sensitive to egg or milk for example, and the child may be able to tolerate the allergen cooked even if they still cannot tolerate them raw). So it is important to reassess your own or your child's allergies regularly so as to avoid unnecessary food restrictions. However, this must only be done under medical supervision.

First published October 2012.

 

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