PARENTS who keep their homes obsessively clean could be causing their children to develop life-threatening nut allergies, researchers claim.

According to the Royal Children’s Hospital in Melbourne, as many as one child in 200 could have a peanut allergy – and that number has doubled since 1995.

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 per cent 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.