Why do some allergies get more severe over time?


I was reminded of this just now while reading another post. I remember reading that some allergies (like food allergies) get progressively worse with exposure, but after googling I couldn’t find a solid answer, and some results even said it was a myth.

In my personal experience, my tree nut allergy went from very mild as a kid to life threatening by my twenties. So if it’s not exposure that causes worsening allergies, what is it actually?

Is there something that does make allergic reactions get worse over time? Or is it just a thing we don’t actually know the reason for?

In: Biology

Allergies are complicated. Some get randomly worse, some randomly stop. Exposure can make it worse or better.

The human immune system is pretty unpredictable.

My understanding (also have an allergy that went from mild to life threatening) is that histamine being released is a natural defense your body releases to get something it deems unsafe out of your body and keep it out (runny nose, watery eyes, etc). When you first encounter an allergen, your body responds to it as a new threat. Your body isn’t prepared to fight it off, but with future encounters, your body now knows the allergen, views it as a threat and does everything it can to get it out. The problem is that the body is overreacting, which leads to anaphylaxis.

It’s similar to how your immune system reacts to illnesses. Once you’ve had the chicken pox, your body recognizes it and fights it off. It knows it’s a threat and how to handle it, so your body does what it needs to do.