Allergic to Peanuts? Anaphylaxis? Lethal

Peanut butter smeared thickly onto fat slabs of bread is a favourite of schoolchildren everywhere. But for some individuals, the merest hint of peanut can be lethal.

Each year in the UK, several people are killed by an anaphylactic reaction to nuts. Anaphylaxis is a sudden, severe, system allergic reaction that can involve various parts of the body including vital organs.

Although the number of fatalities is small, many more people suffer less extreme allergic reactions which can still be serious. Between 5% and 8% of UK children develop a food allergy by the age of two or three, and one in 70 have an allergy to peanuts - double the number a decade ago.

In every second classroom in the UK, statistically there will be one child who has to carry an emergency adrenalin injection in case of a violent peanut reaction. Why so many children are suffering from food allergies is a mystery to scientists.

Currently, parents in the UK and US are advised to avoid peanuts during pregnancy, breastfeeding and the first three years of a child’s life. Many experts believe this may be the root of the problem, because early exposure is necessary to teach the immune system tolerate peanuts.

In Africa, Asia and China, peanuts are a staple food and routinely given to children. Young children are often weaned on "peanut soup" which is considered highly nutritious. The evidence is that in these countries, rates of peanut allergy are lower than they are in the West.


Yet there are conflicting reports from other research which suggests the opposite - that early exposure to peanuts makes an individual more susceptible. So which strategy is the right one? To help answer this question, and understand more about peanut allergy generally, scientists have just embarked on a new seven-year study.

Parents are being asked to volunteer their babies for the £5 million trial, Leap (Learning Early About Peanut allergies), based at the new Evelina Children’s Hospital at St Thomas’ Hospital in London.

All 480 babies taking part will be aged between four months and 11 months, and already have eczema or an allergy to eggs. Studies have shown that a quarter of infants with these conditions will develop a peanut allergy.

Despite the dangers of peanut allergy, the scientists conducting the trial insist the children will be safe. "It is certainly not the case that we are putting children at risk," said lead researcher Professor Gideon Lack, from King’s College, London.

"We’ve thought very deeply about this study. Our current policies may be the root of the problem, we don’t know, but simply to sit back and accept the situation we believe would be unethical."

All the children would be carefully looked after and rigorously monitored by dieticians, he said.
They will be randomly separated into two groups. One will receive snacks containing six grams of peanuts a week - the equivalent of 10 to 20 peanuts - for three years. The other infants will be given a diet completely devoid of peanuts.

Both groups will be assessed for peanut allergy at the age of five. Prof Lack belongs to an allergy-investigating team at the London-based MRC-Asthma UK Centre in Allergic Mechanisms of Asthma.

The centre’s director Professor Tak Lee said: "The evidence to support current guidelines for preventing peanut and other food allergies is lacking. This large trial should provide robust evidence to help inform the right course of action as well as offering a unique opportunity to investigate how and why food allergies develop."