A peanut allergy is one of the most common types of food allergies, and is a very serious condition that can result in death. It occurs when a person’s immune system overreacts to exposure to peanuts or products with peanut proteins. According to the American Academy of Allergy, Asthma and Immunology (AAAAI), about 1.5 million people suffer from a severe peanut allergy. The only way to successfully treat a peanut allergy is to completely remove peanuts and foods containing peanuts from the diet.

Peanuts are actually part of the legume family (along with peas, beans and lentils) and are a type of seed. About a quarter of the peanut kernel is made up of proteins, many of which are known allergens. Almost half of those individuals who are allergic to peanuts also have cross-reactivity to some form of tree nuts.

Allergic individuals who have been exposed to a peanut protein will usually begin to experience symptoms in a few minutes to a few hours. Symptoms include swelling, hives, itchiness, nausea and stomach pain. Severe reactions can result in anaphylactic shock, which includes difficulty breathing and a drop in blood pressure.

The body response that occurs when an allergic individual encounters a peanut protein is called an allergic cascade and includes the following steps:

• The immune system responds when a peanut protein enters the body. This usually occurs by eating peanuts or peanut components. However, in some individuals it can also occur through skin contact or even inhaling peanut fumes.
  
  
• The immune system reacts by perceiving the protein to be a dangerous threat. To combat the threat, the body triggers the release of IgE antibodies.
  
  
• The IgE antibodies trigger the release of histamines and other chemicals from mast cells and basophils. It is these chemicals that are responsible for most allergy symptoms.

For reasons that are not yet known, peanut allergies can be triggered by a very tiny amount of peanut protein – much less than for any other type of food allergy. As a result, peanut allergies can be triggered very easily. Some highly sensitive individuals can have an allergic response simply by kissing or having skin to skin contact with another person who has recently eaten peanuts.

Some foods that are packaged in the same facilities as peanuts, but do not contain any peanut ingredients themselves, may cause reactions in highly sensitive individuals. Therefore, food packaging may indicate that the food was processed on equipment that also processed foods containing peanuts. This statement will not be in the ingredient section, but may appear on the food label. The U.S. Food and Drug Administration does not require this notice to appear on food labels, but does encourage its use. When in doubt about a product, consumers are encouraged to contact the manufacturer.

Even thermal and chemical treatment of the peanuts (as occurs with cooking or processing) is not effective at reducing the strength of peanut allergens. Occasionally, these processes will even increase the allergen’s strength. Again, this is different from most other food allergies, in which cooking or chemically treating foods tends to reduce the allergic response.

A number of recent studies have shown that the prevalence of peanut allergies is growing in children. While there is currently no conclusive explanation for this phenomenon, many researchers attribute the trend to the rising numbers of children who are eating peanuts at a very young age. Exposure to an allergen at a young age may lead to the development of an allergy to that substance.

Another theory for this increase involves the peanuts themselves. Some believe that processes used to prepare peanuts (e.g., roasting) are making them more likely to trigger allergic reactions. Finally, peanuts are being used in increasing numbers of products, such as topical creams, which may also contribute to the increase in allergies.

Although the incidence of peanut allergies in children is on the rise, up to 20 percent of young children outgrow their peanut allergy. Studies have not been conducted on older individuals.