Peanut allergies, children and pregnancy

About 1 percent of children and adults in the United States are allergic to peanuts and peanut products, including peanut butter and any food containing peanuts (1, 2). For reasons that are not well understood, peanut allergy has doubled in the past decade (3). Individuals with a peanut allergy can have a serious (such as difficulty breathing and loss of consciousness) or even fatal reaction if they eat peanuts. This reaction occurs because the immune system of an affected individual reacts abnormally to usually harmless proteins in peanuts. Children and adults who are allergic to peanuts should not eat them at any time. Unfortunately, there is no proven way to prevent peanut allergy in a child.

Which foods may contain peanuts?
Besides peanut butter and peanut oil, some foods that may contain peanuts include:

  • Arachis oil (another name for peanut oil)
  • Many ethnic foods, including Chinese, Mexican, Thai and Vietnamese
  • Many candies, especially chocolate (which often is made on machinery that also processes candies made with nuts)
  • Some cereals, including granola
  • Marzipan
  • Pesto sauce
  • Some veggie burgers
  • Some health food bars

Should a pregnant woman eat peanuts or peanut products?
Women who are allergic to peanuts should not eat peanuts or peanut products during pregnancy or at any other time. Studies suggest that women who are not allergic to peanuts can safely eat peanuts during pregnancy (3).

Because peanut allergy tends to run in families, health care providers have been seeking ways to help prevent this allergy in babies from affected families. Until recently, experts recommended that women who aren’t allergic to peanuts but who have a family history of peanut allergy avoid peanuts during pregnancy (3, 4). However, recent studies have found no evidence that avoiding peanuts in pregnancy helps prevent peanut allergies in the child (3, 5).

Peanuts can be healthy food choices for pregnant women. Peanuts are a good source of protein and folate. Folate is the form of folic acid that is found naturally in foods. Taking folic acid before and during early pregnancy helps prevent certain serious birth defects of the brain and spine. The March of Dimes recommends that all women who could become pregnant take a multivitamin containing 400 micrograms of folic acid daily, and make healthy food choices that include foods rich in folic acid.

Is it safe to eat peanuts while breastfeeding?
If a woman is not allergic to peanuts, she can eat peanuts and peanut products while breastfeeding. There is no evidence that avoiding peanuts during breastfeeding helps prevent peanut allergies in the child (3, 5).

Is it safe for infants and young children to eat peanuts and peanut products?
Infants and young children who have been diagnosed with a peanut allergy should never eat peanuts or peanut products. Until recently, experts recommended delaying introduction of peanuts and peanut products to children with a family history of peanut allergy until age 3 (4). Recent studies suggest that this delay does not help prevent peanut allergy (3).

In fact, a 2008 study found a 10-fold greater risk of peanut allergy in children who did not eat peanuts in infancy and early childhood compared to those who ate high quantities of peanuts (6). Additional studies are needed to determine whether eating peanuts in early childhood can help prevent peanut allergy in high-risk children.

Can exposures other than food contribute to the development of peanut allergy?
One study suggests that using lotions (such as diaper creams) containing peanut oil, especially when the baby has broken skin, may increase the risk of the baby having peanut allergy (5). While lotions containing peanut oil are not commonly used in this country, this study suggests that exposures other than food may contribute to peanut and other food allergies.

At what age do children develop symptoms of peanut allergy?
A peanut allergy often is diagnosed in children in the first 2 years of life, though it can develop at any age (2, 7).

What are the symptoms of peanut allergy?
Someone who is allergic to peanuts usually develops symptoms within seconds to 2 hours after eating a food that contains peanuts (2). Symptoms range from mild to severe and can include:

  • Tingling in the mouth
  • Hives (itchy bumps on the skin)
  • Swelling of the tongue and throat
  • Abdominal cramps
  • Vomiting and/or diarrhea

The most serious reaction is called anaphylaxis. In such cases, blood pressure drops suddenly and the individual loses consciousness. This condition requires emergency medical treatment.

How is peanut allergy diagnosed?
Peanut allergy usually is diagnosed by doctors who specialize in treating allergies. The child’s health care provider can provide a referral to an allergy specialist. The specialist most likely recommends a skin test and/or a blood test to help diagnose peanut allergy.

How is peanut allergy treated?
There is no drug or “allergy shot” that can prevent an allergic reaction when a person with peanut allergy eats peanuts or any food containing peanuts.

Treatment involves avoiding peanuts and any foods that may contain them. This can be difficult because many foods contain peanuts. Affected individuals must carefully read food labels, and children must be taught not to eat someone else’s foods outside the home. Most providers also recommend that they avoid eating tree nuts (such as walnuts, cashews, pecans and pistachios) because up to half of those allergic to peanuts are allergic to at least one kind of tree nut (7).

Children and adults (including pregnant women) with a peanut allergy should carry with them a shot of epinephrine (a medicine that helps control serious reactions). This medicine comes in an easy-to-use pen-shaped device. Epinephrine helps reverse an anaphylactic reaction. A pregnant woman should use this medication as she normally would if she were not pregnant and then go to the hospital or see her health care provider. Prompt treatment usually protects mother and baby. Allergy medicines called antihistamines also help ease symptoms, but they do not work as well as epinephrine.

Parents of children with a peanut allergy should develop a written action plan with their child’s health care provider to give to all caretakers and school personnel. An action plan can help these individuals recognize a child’s allergic reaction and tell them what to do if one occurs. A sample action plan form is available from the Food Allergies and Anaphylaxis Network.

Do children outgrow a peanut allergy?
In most cases, peanut allergy lasts for life. However, about 1 in 5 affected children appears to outgrow peanut allergy (1, 2, 7). An individual who has outgrown a diagnosed peanut allergy should not start eating peanuts unless a health care provider says it is safe.

See also: Food Allergies and Anaphylaxis Network

References

  1. Chapman, J.A., et al. Food Allergy: A Practice Parameter. Annals of Allergy, Asthma and Immunology, volume 96, March 2006, pages S1-S68.
  2. Burks, A.W. Peanut Allergy. Lancet, volume 371, number 9623, May 2008, pages 1538-1546.
  3. American Academy of Pediatrics Committee on Nutrition. Effects of Early Nutritional Interventions on the Development of Atopic Disease in Infants and Children: The Role of Maternal Dietary Restriction, Breastfeeding, Timing of Introduction of Complementary Foods, and Hydrolyzed Formulas. Pediatrics, volume 121, number 1, January 2008, pages 183-191.
  4. American Academy of Pediatrics Committee on Nutrition. Hypoallergenic Infant Formulas. Pediatrics, volume 106, number 2, August 2000, pages 346-349.
  5. Lack, G., at al. Factors Associated with the Development of Peanut Allergy in Childhood. New England Journal of Medicine, volume 348, number 11, March 2003, pages 977-985.
  6. Du Toit, G., et al. Early Consumption of Peanuts in Infancy is Associated with a Low Prevalence of Peanut Allergy. Journal of Allergy and Clinical Immunology, volume 122, number 5, November 2008, pages 978-985.
  7. Skripak, J.M., Wood, R.A. Peanut and Tree Nut Allergy in Childhood. Journal of Pediatric Allergy and Immunology, volume 19, June 2008, pages 368-373.

January 2009

Most common questions

How much weight should I gain during my pregnancy?

The exact amount of weight you need to gain depends on how much you weigh before pregnancy and your Body Mass Index (BMI). Below are some guidelines, but talk to your health provider about your specific pregnancy weight gain goals.

If you began pregnancy at a healthy weight, you should gain 25 to 35 pounds over the 9 months. If you gain between 1 and about 4 ½ pounds in the first trimester, you should put on about 1 pound every week in the second and third trimesters.

If you began pregnancy underweight, you should probably gain about 28 to 40 pounds. If you gain between 1 and about 4 ½ pounds in the first trimester, try to gain slightly over a pound a week in the second and third trimesters.
If you began pregnancy overweight, you should gain only 15 to 25 pounds over the 9 months. If you gain between 1 and about 4 ½ pounds in the first trimester, you should put on slightly over ½ pound every week in the second and third trimesters. While you don't want to gain too much weight, never try to lose weight during pregnancy because that could harm your baby.

If you were obese (with a BMI over 30) at the start of your pregnancy, you should gain only 11 to 20 pounds over the 9 months. If you gain between 1 and about 4 ½ pounds in the first trimester, aim for gaining slightly under ½ pound every week in the second and third trimesters.

Is it safe to eat cold cuts when I'm pregnant?

It's not safe for pregnant women to eat deli meats (such as ham, turkey, salami and bologna) or hot dogs unless the food has been thoroughly heated and is steaming hot. These foods can cause a form of food poisoning called listeriosis and is caused by bacteria. Heating deli meats until steaming hot will kill the bacteria if it's present.

Listeriosis is especially dangerous during pregnancy. Most people don't get sick when they eat food contaminated with listeria. But healthy pregnant women are more likely than other healthy adults to get listeriosis and are more likely to become dangerously ill from it.

The flu-like symptoms of listeriosis can sometimes advance to potentially life-threatening meningitis (infection of the membranes covering the brain, with symptoms such as severe headache and stiff neck) and blood infection. Contact your health care provider if you're pregnant and you develop any of these symptoms.

Is it safe to eat fish raw or seared during pregnancy?

You should avoid all raw or seared fish when you're pregnant. (Seared fish are typically not fully cooked throughout.) Raw fish, including sushi and sashimi, and undercooked finfish and shellfish (including oysters, clams, mussels and scallops) are more likely to contain parasites or bacteria than cooked fish. 


Avoid swordfish, shark, king mackerel and tile fish, even when cooked. These fish have more mercury than other fish. Mercury can be transferred to your growing baby and cause serious health problems. Stay away from game fish, too, until you check its safety with your local health department. A game fish is any fish caught for sport, such as trout and bass.


The USDA recommends that pregnant women limit their fish consumption to 12 ounces of a variety of cooked fish per week.


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