London - Parents who keep their homes obsessively clean could be causing their children to develop life-threatening nut allergies, researchers claim.
In the past 20 years the number of British children with the condition has doubled – with the sharpest increase among the middle classes.
Scientists say their findings support the theory that youngsters from wealthier families have a weakened immune system because they live in cleaner homes.
Their study examined 8,306 patients, 776 of which had some form of reaction to peanuts, and the findings were presented at the annual meeting of the American College of Allergy, Asthma, and Immunology.
Lead study author, allergist Dr Sandy Yip, said: “Overall household income is only associated with peanut sensitisation in children aged one to nine years.
“This may indicate that development of peanut sensitisation at a young age is related to affluence, but those developed later in life are not.”
Researchers also found that peanut allergy was generally higher in males and ethnic minorities.
“While many children can develop a tolerance to food allergens as they age, only 20 percent will outgrow a peanut allergy,” said ACAAI president Dr Stanley Fineman.
Nut allergies commonly cause breathing problems and occasionally result in death through anaphylactic shock.
Last year, researchers at Edinburgh and Maastricht universities studied records from more than 400 GP practices in England between 2001 and 2005 to determine the number of patients with an allergy.
The study showed more than 25,000 people in England have been diagnosed with a nut allergy at some point in their lives.
It also found that children from a more affluent background were twice as likely to have a peanut allergy compared to their poorer counterparts.
* One British child in 50 has a peanut allergy – double the proportion of two decades ago.
The majority of allergic reactions to nuts are mild, with hives, eczema and vomiting the most common complaints.
Until 2009, the Food Standards Agency warned women to avoid peanuts in pregnancy and while breastfeeding if there was a family history of allergies.
The advice was later altered after a major review of scientific evidence showed there is no clear link between eating peanuts at a young age and developing an allergy in later life. - Daily Mail