Signs of an allergic reaction to peanut butter include hives on the skin and other skin reactions, such as eczema. Some people may have stomach and digestive trouble as a result of an allergic reaction to peanut butter. Other signs of this allergy include common allergy symptoms such as coughing and sneezing. In some cases, the reaction can be severe and lead to anaphylaxis.

A rash or other reaction on the skin is a very common allergic reaction to peanut butter and other foods. Usually, a skin reaction is considered a mild reaction. A person may break out into hives or raised red rashes on the skin or experience swelling on the face. There may also be a feeling of itchiness or tingling when an allergic person is exposed to peanuts or peanut butter. Eczema is another common allergic reaction to peanuts and other foods.

Some people experience digestive problems as an allergic reaction to peanut butter. They may have diarrhea or vomiting after eating it. Stomach pains and cramps as well as nausea can also occur as an allergic reaction to peanut butter.

More general signs of an allergic reaction can occur after a person is exposed to peanuts. His eyes may water, and his nose may be congested or runny. Sometimes peanut butter can trigger an asthma attack in a person who is allergic. A person can experience wheezing, shortness of breath, and coughing. Some people may feel as though they will faint or have chest pain.

Peanut allergies can usually cause a very severe reaction, even if a person is exposed to only a very small amount of peanuts or peanut butter. Anaphylaxis is a very common reaction in people who are allergic to peanuts. Signs of anaphylaxis include a sudden drop in blood pressure and swelling in the throat that makes breathing difficult. A person may pass out or become extremely dizzy. Usually, the heart rate increases.

When someone experiences anaphylaxis, she needs to go to the emergency room right away. Typically, a person with a severe peanut allergy will carry an epinephrine injector, which she can inject into the thigh when a severe reaction occurs. People with minor reactions may recover with over-the-counter antihistamines.

The best way to prevent an allergic reaction to peanut butter is to avoid the ingredient completely. An allergic person needs to be diligent about reading food labels and eating only foods that are guaranteed to be free of peanut butter or peanuts. Some people need to be careful about eating tree nuts such as almonds, as they may trigger a similar reaction.