The research found that children from a more affluent background were twice as likely to have a peanut allergy than their poorer counterparts.
Peanut allergy commonly causes breathing problems, but occasionally results in fatal anaphylactic shock.
The number of British children with the condition, which can be fatal in extreme cases, is believed to have doubled in the past 20 years, the 'Daily Mail' reported.
The increase is sharpest among the children of wealthy middle-class parents who keep their homes excessively clean and dirt-free.
Scientists say the findings support the theory that youngsters from wealthier backgrounds enjoy an excessively clean lifestyle, leaving their developing immune systems unfamiliar with many germs.
When they are later exposed to new irritants, including harmless foods such as nuts, their body is more likely to have an allergic reaction.
More From This Section
The study examined 8,306 patients, 776 of which had some form of reaction to peanuts.
"Overall household income is only associated with peanut sensitisation in children aged one to nine years," said lead author of the study, Dr Sandy Yip.
"This may indicate that development of peanut sensitisation at a young age is related to affluence, but those developed later in life are not," he said.
Researchers also found that peanut allergy was generally higher in males and racial minorities.
"While many children can develop a tolerance to food allergens as they age, only 20 per cent will outgrow a peanut allergy," said American College of Allergy, Asthma, and Immunology (ACAAI)president Dr Stanley Fineman.