An Allergic reaction to Peanuts can happen liturally minutes after consumption. Peanut allergy symptoms can range from mild to severe depending on the persons. The specific allergy reactions can include the following:
The peanut allergy is the most common anaphylaxis reaction, meaning it is the most common reaction to cause life threatening reactions.
It is not completely clear why peanuts affect people who are allergic to peanuts. But the reaction happens when your immune system over reacts and releases chemicals including Histamine. Your body for whatever reason seems to think that the peanut is a harmful alien, instead of treating the peanut like any other food.
It is the Histamine release that causes the above symptoms, not the peanut itself.
A peanut allergy, not to be mistaken for a "nut allergy" is a "peanut allergy". Often people make the mistake of thinking that they are the same allergy.
A nut allergy is caused by being alergic to Chestnuts, Hazelnuts, Pistachio , and others. Peanuts are completely different they are not actually a nut, its a Legume.