Beware of what you eat

Allergic reaction to peanuts has increased in the United States

Peanut allergy is common and is the leading cause of food allergy in adults and children. Reasons for this are not clear. Peanut is a cheap source of high quality protein. Therefore, more and more peanuts are used in energy bars and other protein rich foods. Pregnant women were encouraged to eat more peanuts for the same reason.

With international travel and availability of exotic oriental cuisines, exposure to peanut becomes more widespread. More peanuts are consumed in China and India than here, but the incidence of peanut allergy is much lower in these countries. Unlike in the west, in China and India peanuts are cooked and not roasted before consumption. It is believed that exposure to high temperatures during roasting alters the protein structure in peanuts and increases the chances of developing allergy to peanuts.

I am allergic to peanuts. Could I eat other nuts, legumes and foods made in peanut oil?

Peanuts are legumes and not true nuts like cashews, almonds, etc. Botanically, they are not related. However, up to 33 percent of people who are allergic to peanuts may also be allergic to tree nuts. This is called co-sensitization-simultaneous development of allergy to botanically unrelated proteins. If you are allergic to both, you should avoid both. Peanut oil if not processed properly may contain trace amounts of peanut proteins and cause anaphylaxis in truly peanut-allergic patients. Soybean, green peas, navy beans, garbanzo beans, etc., are also in the legume family. A person who is allergic to peanuts may not be allergic to other legumes even though he or she may test positive for other legumes on allergy skin or blood testing. Talk with your allergist if you need more clarification in this regard.

How is peanut allergy diagnosed?

Peanut allergy is diagnosed by taking a good history and by doing allergy skin test or blood test. History is more important of the two. If your history suggests anaphylaxis to peanuts, it is safer to do blood tests and avoid skin tests. However, the risk of experiencing a serious systemic reaction is minimal even with skin tests.

In doubtful cases where peanut allergy is suspected, clinically and both skin and blood tests are negative, your allergist may subject you to peanut challenge studies under his or her direct supervision in his or her office or hospital. Bear in mind up to 2/3 of such challenges may cause serious allergic reactions and should not be attempted by you without your doctor being physically there with you. Equipment and trained personnel to take care of emergencies should be available before undertaking such challenges.

Okay, I have peanut allergy. What can I do about it?

Once you are diagnosed with peanut allergy, you should avoid peanuts and foods containing peanuts for the rest of your life. Less than 20 percent of people who are allergic to peanuts outgrow the allergy. Some of the strategies you may have to learn include the following: always read food labels, make your house peanut- and tree nut- free, beware of cross-contamination due to improper washing of utensils, check with a restaurant manager or chef before eating out, give your child's school a copy of a food allergy action plan if your child is allergic to peanuts, educate your child about not sharing food with others, wear a MedicAlert bracelet and ensure you or your affected family member have two EpiPens available at all times and know how to use them. Call 911 after using EpiPen.

Is there hope?

Research is going on at present to produce allergy-free peanuts by using genetic engineering techniques. Studies were attempted to give peanut allergic patients Xolair injections (at present used to treat severe asthma) in order to reduce sensitivity to peanuts in such patients. Such studies had to be abandoned due to adverse reactions in study subjects. Peanut allergy injection is not an option at present for the same reasons. Early screening for food and environmental allergies is recommended for children born in high-risk (allergy-risk) families.

At present, the best policy seems to be not to introduce peanut-containing foods in children's diet until they are 3 or 4 years old. It is also recommended that foods containing peanuts should be avoided by pregnant and lactating women. Until such time that science offers something more definitive and meaningful, education, avoidance and preparedness are the only available strategies to peanut allergic patients.

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Natarajan Asokan, M.D., F.A.A.P. is a board certified allergist and immunologist and a board certified pediatrician with more than 25 years of experience as a physician and seven years of experience as a practicing allergist & immunologist. He treats adults and children with various allergy & immunology problems. He can be reached at 1739 Beverly Ave., Suite 118, Kingman, AZ 86409, 681-5800, Fax: 681-5801, or www.trinityallergy.com