Children who grow up in affluent households are more likely to develop peanut allergy compared to those who live in poorer neighborhoods, a new study suggests.

Researchers say the latest findings support the so called "hygiene hypothesis" theory that says that a living in an overly clean environment may suppress the development of a child's immune system, therefore increasing the risk of developing allergies in the future.

Researchers looked at data for 8,306 patients. Of all the participants, 776 had some form of reaction or an elevated antibody level to peanuts according to the study presented Friday at the annual meeting of the American College of Allergy, Asthma and Immunology (ACAAI), in Anaheim, California.

"Overall household income is only associated with peanut sensitization in children aged 1 to 9 years," study author Dr. Sandy Yip said in a statement. "This may indicate that development of peanut sensitization at a young age is related to affluence, but those developed later in life are not."

Yip and her team found that peanut allergy was generally higher in males and ethnic minorities regardless of age. Researchers also found that peanut-specific antibody levels peaked when children were between 10 and 19 years old, but tapered off after middle age.

"While many children can develop a tolerance to food allergens as they age, only 20 percent will outgrow a peanut allergy," Dr. Stanley Fineman, ACAAI president, said in a news release. "It's important that children remain under the care of a board-certified allergist to receive treatment."

Peanut allergy affects about 400,000 children living in the United States. Peanut allergy is one of the food allergies most commonly associated with sudden and severe allergic reactions that can occasionally result in death through anaphylactic shock.

Experts recommend that people with peanut allergy be vigilant in restaurants because peanuts may appear as a hidden ingredient in sauces or marinades. They say that people with food allergies should also carry an allergist prescribed epinephrine in case of an emergency.

While the study found an association between household income and peanut allergy in young children, researchers stressed that it did not prove a cause-and-effect relationship. Studies presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.