Are allergies on and off?

For the first time in the 17 years I've lived I've become effected by the pollen in the air. Is it normal for people who never were effected by allergies to suddenly have them?

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Answer:
It happens. They have the ability to develop without warning, and can even go away without warning. They don't typically come and go both. Usually you either get them, or you lose them, not both.

I'd recommend eating some locally made honey. It's like an immunization against the pollen.

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Answer:
They aren't on and off, but yes it is very possible to suddenly develop an allergy to something that you previously weren't allergic to.