Last reviewed by Faculty of Harvard Medical School on December 29, 2009
By Claire McCarthy, M.D.
Boston Children's Hospital
It seems as if peanut allergy stories are in the news more and more these days, especially when they involve a child dying after eating something as innocuous as a cookie.
"Peanut-free" classrooms and cafeteria lunch tables are becoming commonplace in schools. Food labels must now clearly state if a product contains any peanuts. What's going on?
Peanut Allergy on the Rise
According to the best data we have, the incidence of peanut allergy doubled between 1997 and 2002, and the numbers certainly haven't gone down since then.
Experts don't know exactly why peanut allergy is on the rise but some possible explanations include:
- changes in the structure of the protein in peanuts due to high temperatures used in the dry-roasting process that makes them more likely to cause allergy
- repeated exposure especially beginning in childhood to peanuts and peanut products, which are everywhere and may cause a reaction in some people
- early exposure to peanuts either prenatally or through breast milk when the immune system isn't completely developed
The Harsh Reality
Whatever the reason, peanut allergy is on the rise and here to stay. So why all the fuss?
Peanut and tree-nut allergies cause the most severe food-induced allergic reactions. While other food allergies can cause rashes or hives or asthma, peanut allergy can be deadly.
People allergic to peanuts can have an extreme allergic reaction called anaphylaxis, where the face and breathing tubes swell up, causing severe breathing difficulties. Blood vessels also expand, causing a dangerous drop in blood pressure. Without swift treatment, anaphylaxis can kill.
Even scarier is the fact that avoiding peanuts is harder than you might think. It's not as simple as not buying peanut butter. Peanuts are in all sorts of unexpected places, like salad dressings (as peanut oil), baked goods, ice cream and many candies. And since just trace amounts can cause a reaction, foods prepared on the same machines that prepare foods with peanuts must be avoided as well. A smear of peanut butter on the table that accidentally mixes with the allergic person's food or get on their hands can be dangerous for the same reason.
Not only that: around half of the people who have a peanut allergy also have a tree nut allergy (peanuts arent actually nuts, they're legumes like beans and peas), making things like almonds, walnuts and pecans a problem as well. Many have additional food allergies.
Stay on the Alert
Having a peanut allergy is life-changing. And because only about 20% are outgrown, it can be a life-long issue.
Some new injectable treatments are in the works to prevent severe reactions to peanuts, but they are still in the research stage. For now, if your child has a peanut allergy, the key lies in being vigilant and being prepared. Here's what you need to do:
- Let everyone know. School personnel, day care staff, family, friends, parents of friends need to know that your child is allergic. A medical alert bracelet is a good idea.
- Have EpiPens everywhere: home, school, day care, Grandma's house, anywhere your child spends time. EpiPen is an auto-injector that administers epinephrine, the best emergency treatment for a severe reaction or anaphylaxis. Carry one with you at all times and have your child do the same. Your doctor can give you a prescription for as many as you need. Make sure people know how to use them. When it comes to anaphylaxis, seconds count.
- Keep diphenhydramine (Benadryl) handy, too. Diphenhydramine can prevent a mild reaction from turning into a severe one, and may be a good idea to give along with the EpiPen (talk to your doctor).
- Get educated. To learn more about peanut allergy and high-risk foods to avoid go to The Food Allergy & Anaphylaxis Network. It has information about hidden sources of peanuts and resources for managing food allergies.
- Educate your child, too. As soon as he is old enough, teach him foods to avoid. Just as importantly, teach him not to trade food or take food from others. Your child should also know the signs of an allergic reaction and be able to tell a grownup immediately if they occur.
- Become a fanatical label reader. At the beginning of 2006, the Food Allergen Labeling and Consumer Protection Act went into effect. Food makers are now required to clearly state on food labels when a packaged food contains peanuts or another major food allergens (milk, eggs, fish, wheat, shellfish, soybeans, and tree nuts).
- To the extent that it's possible, don't let others feed your child. Pack snacks and lunches even for play dates. Have your child's teacher let you know about birthday celebrations so you can send in a peanut-free treat. When dining out, if you're unsure about the menu, bring along an alternative meal just in case (be especially careful in restaurants).
- Make an appointment with an allergist. The allergist can test your child for other food allergies and help you have everything you need to prevent reactions.
As with everything else that's important in your child's life, protecting your child from peanut exposure takes commitment and can't be done alone. But everyone working together you, your child, and your community can help keep your child safe.
Claire McCarthy, M.D., is an assistant professor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, and medical director of the Martha Eliot Health Center, a neighborhood health service of Children's Hospital. She is a senior medical editor for Harvard Health Publications.