Is it possible to develop a peanut allergy all of a sudden later in life?

I had a really bad time last night. Around 11:00 PM I was hungry so I ate a snack of 2 ounces of peanuts. I opened up a new jar of peanuts. About 20 minutes later I developed a horrible and painful itching all over my body and extremities. I couldn't stop itching. I couldn't itch fast enough! I never experienced itching like that. It lasted about 50 minutes. Seems like an allergic reaction. But I never had a reaction to peanuts in my life. Is it possible to develop a peanut allergy late in life? Now, I'm afraid to eat peanuts. When I eat peanuts again, I'm going to try just a half ounce and see what happens. Anyway, needless to say, I threw away that jar of peanuts!! Any thoughts?

curiosi · 61-69, F

Most food allergies start in childhood, but they can develop at any time of life. ... The most common foods that cause food allergy in adults are peanuts, fish, shellfish (shrimp or lobster) and tree nuts (almonds, walnuts, pecans and cashews).