Have you seen peanuts served on an airplane recently? If not, it's because approximately one percent of us are allergic to peanuts. For some of that one percent, it is possible that simply breathing in the fumes of a peanut can be fatal - in fact, peanut allergy is one of the most common causes of food-related deaths, and the prevalence appears to be rising among children. Most children do not outgrow peanut allergies!Note that peanuts are not actually tree nuts - they are legumes, like peas, beans, lentils, and soy. However, over a third of those who are allergic to peanuts are also allergic to tree nuts, and vice-versa. (Cashews, walnuts, pecans, and almonds are the most common allergy-causing tree nuts.) Peanut allergies usually result in symptoms within minutes of exposure, and range from mild to severe. There may be skin reactions including hives, redness or swelling; itching or tingling in or around the mouth and throat; shortness of breath or wheezing; tightness of the chest; runny or stuffy nose; and vomiting, diarrhea and abdominal pain. It is one of the most common causes of anaphylaxis, a medical emergency that is treated with epinephrine (adrenaline) and a trip to the emergency room. Anaphylaxis results in the constriction of the airways, swelling of the lips and throat (making it difficult to breathe), a severe drop of blood pressure (shock), rapid pulse, dizziness, lightheadedness, loss of consciousness, and even death. Peanut allergies occur when the immune system mistakenly identifies peanut proteins as foreign and harmful. The reason why some develop an allergy to peanuts is unknown, and there doesn't appear to be a link to exposure to peanuts during pregnancy or during breast-feeding. One interesting hypothesis is that a later introduction of children to peanut products significantly increases the risk. This theory is supported by a joint study conducted in the United Kingdom and Israel, which found that Israeli children were given peanuts at a much younger age, and that children in the United Kingdom had ten times the risk of developing peanut allergies. We do know that certain factors increase the chance of having peanut allergies: •Being young - Food allergies are most common in children, especially toddlers and infants. As we grow older, our digestive system matures, and the body is less likely to react to allergy triggers. •Having had a past peanut allergy - Twenty percent of children with peanut allergies appear to outgrow them, but they may recur. •Having other allergies - Having any type of allergy, such as hay fever, skin allergies, or other food allergies, puts you at a higher risk for peanut allergy. •Having family members with allergies - Peanut allergies tend to be inherited. How does exposure take place? The most obvious and dangerous route is internal, through eating a peanut. Reactions, however, can also be a result of external exposure. Some experts now believe that allergic reactions can be triggered by simple touch or smell, and it is this belief that has led to the banning of peanuts in many airplanes, schools, medical facilities, and even in some public places. There is considerable controversy remaining on the subject of external exposure and allergic reactions, and the research continues. Note that there is a difference between food intolerance and food allergies. Those with peanut intolerance might be able to eat peanuts and suffer only mild symptoms, such as indigestion or heartburn. Peanut intolerance does not involve the immune system, and eating a small amount of peanuts does not generally trigger a serious reaction. To diagnose a peanut (or any food) allergy, look for a close relationship between consuming the food and showing symptoms. Skin testing is used to diagnose an allergy: a small amount of the suspected food is placed on the skin of the forearm or back, and the skin is pricked with a needle to allow a tiny bit beneath the surface. A reaction will occur if there is an allergy. Less accurate than skin tests, blood tests can also measure the immune response. Sadly, the only current treatment for peanut allergies is to treat symptoms when they arise. Some allergists are showing promising results through oral immunotherapy, giving children minuscule amounts of peanuts in order to desensitize the immune system. Herbal medicines and even a vaccine are being researched. However, for now, strict avoidance is the only way to avoid an allergic reaction. Minor reactions can be treated with over-the-counter medications (such as Benadryl) or prescribed antihistamines, but severe allergic reactions may require epinephrine and an emergency room. Anyone with a peanut allergy is instructed to carry epinephrine injectors at all times. People with peanut allergies must learn to develop a strict and careful lifestyle regarding exposure. Always read labels. Even a trace amount of exposure can produce a severe reaction; don't ignore a label that says a food was produced in a factory that processes peanuts. When in doubt, just say no. Let everyone in your life know that you have a peanut allergy, and wear a medical alert bracelet or necklace. If you have questions, as always, consult with your physician. Safe eating! Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.
********** Published: December 8, 2011 - Volume 10 - Issue 34