Food allergy occurs when the body’s immune system reacts to
a protein in a certain food, causing the release of antibodies
and histamine. The release of histamine causes symptoms. The
most common foods to which people are allergic include egg,
cow’s milk, peanuts, tree nuts (cashews, almonds, hazelnuts,
walnuts), sesame seeds, soy, wheat, fish and shellfish.
Allergy symptoms can begin within minutes to 2 hours of eating
the problem food. Symptoms can include eczema, hives, facial
swelling, itching or swelling of the lips, tongue or mouth,
vomiting, diarrhoea, itching or tightness in the throat, and
difficulty in breathing.
Symptoms can vary from mild to severe. Even tiny amounts of
a problem food can cause serious reactions in very sensitive
people. Occasionally, a very severe, rapidly progressing and
life-threatening allergic reaction, known as anaphylaxis,
can occur. This requires immediate first aid treatment, for
example with an Epipen adrenaline injection.
True food allergy is most common in children, but only affects
about 1% of adults. Most children will grow out of food allergies
by school age, although seafood and nut allergies tend to