Peanut allergy often appears in the first three years of life, with the allergic reaction to eating peanuts ranging from a minor irritation all the way to a life-threatening, whole-body allergic response called anaphylaxis.

Many children grow out of other food allergies such as milk or eggs, but only about 20pc lose their peanut allergy.

Dr Wesley Burks, a food allergy expert at Duke University Medical Centre in Durham, North Carolina, wrote in the Lancet medical journal that a solution appears to be on the horizon.

"I think there's some type of immunotherapy that will be available in five years. And the reason I say that is that there are multiple types of studies that are ongoing now," Dr Burks said.

Ideally, such a therapy would change a person's immune response to peanuts from an allergic one to a non-allergic one, Dr Burks said.

He said one possible approach is using engineered peanut proteins as immunotherapy.

Other approaches are showing promise, he said, including the use of Chinese herbal medicine in animal research.

Genetic engineering may also produce an allergen-free peanut, Dr Burks said.

But he said that because several peanut proteins are involved in the allergic response, the process of altering enough of the peanut allergens to make a modified peanut that is less likely to cause an allergic reaction would probably render the new peanut no longer a peanut.

"You could end up with a soybean," Dr Burks said.

He said peanut allergy affects about 1pc of children under the age of five and that in the past 15 years more children have been diagnosed with the condition.

He cited research showing the condition becoming more common - doubling among young children from 0.4pc in 1997 to 0.8pc in 2002 in one US study.

It is unclear why it is becoming more common, he said. One theory he cited was the "hygiene hypothesis", which holds that too little exposure to infectious agents in early childhood can raise one's susceptibility to allergic reactions.

Dr Burks said other researchers have suggested that if a pregnant woman eats peanuts, her baby has a higher risk of becoming allergic.

Symptoms of peanut allergy include skin reactions such as hives, itching around the mouth and throat, diarrhoea, stomach cramps, nausea, vomiting, shortness of breath, wheezing and, in severe cases, anaphylaxis - a medical emergency.

SOURCE: Reuters