THE whole of this week is dedicated to increasing the understanding of food allergies, a condition which has seen the number of cases double in the last decade. Thankfully the number of deaths has dropped due to increased public awareness and the requirement for food products to be clearly labelled.

Food allergies are often confused with intolerance to a particular substance. In an allergic reaction, the body’s immune system recognises something in the food, usually a protein, as foreign, and hence releases chemicals to attack it. This produces a reaction which varies from mild itching of the mouth and throat, through to swelling of the lips, tongue and throat and in the worst case an anaphylactic reaction, in which the person’s airway may become so swollen, they cannot breathe.

If you witness this, dial 999 immediately and tell the operator “anaphylactic reaction”.

Allergies usually start in infancy. The most common foods to be allergic to include milk, eggs, peanuts and tree nuts, and fish including shellfish.

Affected children tend to also have other allergy-type diseases including eczema, asthma and hay fever. Allergic reactions may also start in adulthood, so anything that resembles the symptoms above shouldn’t be ignored or dismissed.

There is also a condition called oral allergy syndrome in which fruits and vegetables cause an allergic reaction. However if these are cooked, the proteins are changed and don’t trigger the immune system.

IF you think you or your child have a food allergy, the first thing to do would be consult your routine GP, who can refer you for formal allergy testing. There are home testing kits available, however it is better to be to be seen by a trained professional rather than trying to work it out yourself.

The treatment of allergic reactions starts with antihistamines, and those with proven food allergies are offered injectable adrenaline in the form of a pen, for use in case of a potential anaphylactic reaction.

You should know how to use your pen and always carry it with you, regardless of whether you are planning to eat or not, as many deaths could have been prevented by timely administration of adrenaline. The outlook for children who develop allergies in infancy is good, with many growing out of allergies to milk, eggs, soya and wheat.

Peanut allergies tend to persist into adult life and if you develop a food allergy as an adult, it is likely that it will stay with you long term.

The world of allergy testing is always progressing and the latest research has looked at levels of chemicals in the blood released during an allergic reaction to peanuts.

Usually allergies are tested using skin prick tests or getting the individual to eat the foodstuff. Not only are these time consuming and costly, an oral trial may cause an unpleasant and potentially life-threatening allergic reaction.

Because the blood test is far more sensitive, it is hoped that many incorrect diagnoses will be avoided. This test may hopefully soon be extend to testing for other food allergies.