How Long Does a Reaction to Peanuts Last?

An allergy to peanuts is one of the most common food-related allergies, according to KidsHealth. In some people, an allergy to peanuts can be so pronounced that it is life-threatening. Allergic responses to peanuts can vary based on your particular sensitivity to peanuts -- some people may experience immediate, intense reactions that quickly subside while others may have effects that are longer-lasting.

When you experience an allergic reaction, your body is responding to what it views as a foreign invader. When you consume peanuts, your immune system triggers the production of immunoglobulins, which are antibodies that release chemicals such as histamine. This chemical can irritate a number of your body's systems, ranging from your respiratory to your cardiovascular to gastrointestinal symptoms.

If you are severely allergic to peanuts, your reaction will be almost immediate and involve several body systems. This reaction is called anaphylaxis and causes your blood pressure to drop and your airways to swell, resulting in wheezing. If you have reactions of this level, you likely carry an epinephrine-filled syringe which allows you to inject the medication into your leg to immediately reduce your anaphylaxis symptoms. If you are able to treat your reaction in this manner, it should not last more than a few minutes. You may still need to seek treatment at a hospital or other medical facility to ensure your reaction has subsided.

Peanut allergy reactions can vary from person to person. If yours are less severe, you may experience symptoms such as watery eyes, sneezing, breaking out in hives, vomiting or feeling nauseous. Some of these symptoms may resemble those of seasonal allergies or having a cold. In these instances, the reaction typically lasts less than a day, according to Kids Health. You may wish to take a medication called an antihistamine to reduce the amount of symptom-causing histamine in your body.

If your peanut allergy symptoms last beyond a day or seem to be worsening instead of improving, seek medical treatment. Even if you have had less severe reactions in the past, the level of reaction can escalate over time. Your physician can recommend additional strategies, such as carrying an epinephrine syringe or developing better awareness of peanut-containing foods.