Food allergies are caused when the immune system recognises a food (natural or processed) as a potential "invader" or toxin. Where food allergies are present, irritation, swelling or inflammation occurs immediately after eating. Luckily only 1% of adults, and 3% of children are likely to have or will develop food allergies.

Food allergies: immediate response, outward symptoms.

What is happening ?

When proteins are eaten, the natural digestion process breaks these into pieces or peptides. In some people these peptides can be misinterpreted by the immune system causing anti-body's (IgE's) to be formed. Each time that food is eaten another legion of antibody defences is formed. These IgE's join up with cells known as MAST cells. When the IgE's senses the presence of what it considers to be an "invader" (a bacteria or a toxin or venom), the MAST cell releases a cocktail of chemicals (histamines) that cause the tissues to swell up to seal off the "invader" from the rest of the body

What you might see.

Common food allergy symptoms are spots, hives or irritated skin, runny nose and eyes. Serious allergic reactions can be fatal because when the mouth and throat are affected. Airways can become blocked. Other allergic reactions of the stomach cause pain and/or diarrhoea.

What you should do.

If the event of an immediate allergic reaction, go and see your doctor who can organise tests to identify the cause. If breathing is affected go to casualty. You will get a lot more help if you can give clear and detailed answers to these questions:

Food allergies: Recommended reading

Alex Gazzola has written widely on health, nutrition and lifestyle issues. He is author of Living with Food Intolerance, Sheldon Press 2005.

August 2006. £7.99 & £2p&p

Efficient self-management is vital because of of the lack of healthcare provision in the UK. This supportive unbiased book looks at food allergy myths and facts, including:

What is food allergy
Tests and diagnosis
How to manage adverse reactions to food
Prevention and long-term dietary planning
Treatments - do they really help?
Practicalities including travel and eating out

This book includes coverage of Oral Allergy Syndrome, the largest form of food allergy among the adult UK population.

Did the suspected "allergic" reaction come on quickly, usually within an hour after eating the food?

Does a reaction always happen when that food is eaten?

Did anyone else become ill? How much did the person eat, did others eat the same, more or less?

Were other foods consumed at the same meal?

If at that time allergy treatment was taken (anti-histamines) did the "allergy" symptoms subside?

Was the food cooked or raw?

Repeated exposure to allergens can increase the severity of allergic reactions.

This information is not an offer of any kind of diagnosis. Please contact your GP for more information.