Question: Does the immune system is involved in allergic reactions?

Ben Mulhearn answered on 8 Mar 2018:

Yes! An allergic reaction happens when our immune system reacts against things which don’t harm us. For example, I’m allergic to peanuts. Now a peanut isn’t going to kill a normal person if they eat it, but my immune system thinks it’s a foreign invader, so it attacks it. When it does this, my immune cells release lots of chemicals that make me feel unwell because it thinks the peanut is bad and so tries to get rid of it. In fact, most of the damage isn’t done by the peanut (or other allergen), it’s done by the immune system!