Peanut allergy among children has been growing at an alarming rate over the past decade. It's a very serious condition, and one that sometimes can be fatal.

It's not the only chronic condition that today's child has to counter, of course. Asthma and eczema, to name but two, are also affecting more and more children.

But most of these childhood conditions have at least had a plausible explanation for their cause or causes, and usually it's been one or more environmental factors.

Peanut allergy, however, has remained an enigma. Causes mooted have ranged from breastfeeding mothers to a diet high in peanuts from an early age, but none has seemed too convincing.

Researchers believe they finally have the key after studying 49 children with a proven peanut allergy. They believe that the main cause is the use of creams containing peanut oil to treat problems such as nappy rash, eczema, and dry skin conditions. The risk of an allergy from a cream is heightened if the wound is open or oozing, researchers at St Mary's Hospital, London have posited.

The suspected oils, all over-the-counter remedies, contain peanut oil, nut oils or soy oil. Another risk factor could be the early consumption of peanut butter, they say.

(Source: New England Journal of Medicine, 2003; 348: 977-85).