What causes your body to suddenly develop an allergic reaction to something later on in life that you weren’t allergic to before?

Question

i.e. how does ur body suddenly decide something is dangerous enough to warrant a reaction even tho it didnt cause it before

i might be using these tags wrong yeesh

In: 42

Answer 1

Your immune system is constantly creating and destroying “detectors” basically. The vast majority of them wind up no good and are destroyed.

Every once in awhile, it winds up making one that detects some new form of disease and keeps it.

Very occasionally, it winds up creating one thay false alarms on a benign substance and keeps that, too. From now on, your immune system will detect and react to that even though it doesn’t need to. Otherwise known as an allergy.

The exact mechanisms of this process are not well understood at this time, but we know it happens.