社会经济状况影响幼年花生过敏症

Peanut allergies are rising among American children and one reason might be due to economic status. According to a new study presented at the American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting, greater rates of peanut allergy are found in families with higher economic status. This supports the "hygiene（卫生，保健） hypothesis" of many allergists. This theory believes that a lack of early childhood exposure to germs increases the chance for allergic diseases. Over sanitization might suppress the natural development of the immune system.

"Overall household income is only associated with peanut sensitization in children aged one to nine years," said allergist Sandy Yip, M.D., Major, USAF, lead study author and ACAAI member. "This may indicate that development of peanut sensitization at a young age is related to affluence（富裕）, but those developed later in life are not."

The study examined 8,306 patients, 776 of which had an elevated antibody level to peanuts. Peanut allergy was generally higher in males and racial minorities across all age groups. Researchers also found that peanut specific antibody levels peaked in an age group of 10- to 19-year-old children, 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," said allergist Stanley Fineman, M.D., ACAAI president. "It's important that children remain under the care of a board-certified allergist to receive treatment."

According to the ACAAI, peanut allergy affects an estimated 400,000 school-aged children. It is one of the food allergens most commonly associated with sudden and severe reactions such as anaphylaxis（过敏性）. While avoiding peanuts may not be as difficult as avoiding wheat, there is often the risk of cross-contamination by food manufacturers.

The ACAAI recommends peanut-allergic individuals be vigilant in restaurants, where peanuts may appear as a hidden ingredient. Some chefs may use peanut butter in the preparation of sauces or marinades（腌泡汁）. Those with food allergies should also carry allergist prescribed epinephrine in the event of an emergency.

Information about food allergies can be found at AllergyAndAsthmaRelief.org. More news and research from the annual meeting, being held Nov. 8-13, 2012 can be followed via Twitter at #ACAAI.