Peanut Allergy

Peanut allergy is common, especially in children. Peanut allergy symptoms can range from a minor irritation to a life-threatening reaction (anaphylaxis). For some people with peanut allergy, even tiny amounts of peanuts can cause a serious reaction.

If you or your child has had a reaction to peanuts, tell your doctor about it. Peanut allergy is one of the most common causes of severe allergy attacks.

It’s important to get even a minor reaction to peanuts checked out. Even if you or your child has had only a mild allergic reaction in the past, there’s still a risk of a more serious future reaction.

Symptoms
An allergic response to peanuts usually occurs within minutes after exposure, and symptoms range from mild to severe. Peanut allergy signs and symptoms can include:

  • Skin reactions, such as hives, redness or swelling
  • Itching or tingling in or around the mouth and throat
  • Digestive problems, such as diarrhea, stomach cramps, nausea or vomiting
  • Tightening of the throat
  • Shortness of breath or wheezing
  • Runny nose

Anaphylaxis: A life-threatening reaction
Peanut allergy is the most common cause of food-induced anaphylaxis, a medical emergency that requires treatment with an epinephrine (adrenaline) injector (EpiPen, Twinject) and a trip to the emergency room.

Anaphylaxis signs and symptoms can include all of the above, plus:

  • Constriction of airways
  • Swelling of your throat that makes it difficult to breathe
  • A severe drop in blood pressure (shock)
  • Rapid pulse
  • Dizziness, lightheadedness or loss of consciousness

Tests and diagnosis
The following may help determine if you have a peanut allergy or if your symptoms are likely due to something else, such as food intolerance, a bout of food poisoning or some other condition.

  • Description of your symptoms. Be prepared to tell your doctor about your symptoms — such as exactly what happened after you ate peanuts, how long it took for a reaction to occur, and what amount of peanuts or food containing peanuts caused your reaction.
  • Physical examination. A careful exam can identify or exclude other medical problems.
  • Food diary. Your doctor may ask you to keep a food diary of your eating habits, symptoms and medications to pinpoint the problem.
  • Elimination diet. If it isn’t clear that peanuts are the culprit, or if your doctor suspects you may have a reaction to more than one type of food, an elimination diet may be needed. You may be asked to eliminate peanuts or other suspect foods for a week or two, and then add the food items back into your diet one at a time. This process can help link symptoms to specific foods. If you’ve had a severe reaction to foods, this method can’t safely be used.
  • Skin test. A skin prick test can determine your reaction to particular foods. In this test, small amounts of suspected foods are placed on the skin of your forearm or back. Your skin is then pricked with a needle, to allow a tiny amount of the substance beneath your skin surface. If you’re allergic to a particular substance being tested, you develop a raised bump or reaction.
  • Blood test. A blood test can measure your immune system’s response to particular foods by checking the amount of allergy-type antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies. For this test, a blood sample taken in your doctor’s office is sent to a medical laboratory, where different foods can be tested. However, these blood tests aren’t always accurate.

Is it peanut allergy? Or is it peanut intolerance?
Not all reactions to peanuts are caused by an allergic reaction. It can be difficult to know whether you are allergic or intolerant to peanuts.

  • If you have peanut intolerance, you might be able to eat peanuts with only mild symptoms, such as indigestion or heartburn, or no reaction at all. A peanut intolerance doesn’t involve your immune system.
  • If you have a true peanut allergy, eating even a small amount of peanuts may trigger a serious allergic reaction. Tests can help determine whether you have true peanut allergy.

Treatment
There’s no definitive treatment for peanut allergy, but desensitization is showing promise. Desensitization involves giving children with peanut allergies increasing doses of peanut flour or peanut extract over time. Studies have shown promise in desensitizing children to peanuts. More study is needed.

In the meantime, as with any food allergy, treatment involves taking steps to avoid the food that causes your reaction, learning what steps you can take to relieve minor symptoms, and knowing how to spot and respond to a severe reaction.

Being prepared for a reaction
The only way to prevent a reaction is to avoid peanuts and peanut products altogether. But peanuts are common, and despite your best efforts, you’re likely to come into contact with peanuts at some point.

  • For a minor allergic reaction, over-the-counter or prescribed antihistamines may help reduce symptoms. These drugs can be taken after exposure to peanuts to help relieve itching or hives. However, antihistamines aren’t enough to treat a severe allergic reaction.
  • For a severe allergic reaction, you may need an emergency injection of epinephrine and a trip to the emergency room. Many people with allergies carry an epinephrine autoinjector (EpiPen, Twinject). This device is a combined syringe and concealed needle that injects a single dose of medication when pressed against your thigh.

Know how to use your autoinjector
If your doctor has prescribed an epinephrine autoinjector:

  • Carry it with you at all times. It may be a good idea to keep an extra autoinjector in your car or in your desk at work as well.
  • Always replace it before its expiration date. Out-of-date epinephrine may not work properly.
  • Ask your doctor to prescribe a backup autoinjector. If you misplace one, you’ll have a spare.
  • Know how to operate it. Ask your doctor to show you. Also, make sure the people closest to you know how to use it — if someone with you can give you a shot in an anaphylactic emergency, he or she could save your life.
  • Know when to use it. Talk to your doctor about how to recognize when a shot is needed. For a mild allergic reaction to peanuts, it may be OK to go to straight to the emergency room without using an autoinjector. However, if you’re not sure whether the reaction is severe enough to warrant a shot, it’s usually better to err on the side of caution and use the emergency epinephrine.