Seasonal allergies: Pre-class activities

Seasonal allergies, also called hay fever, or allergic rhinitis, are a hypersensitive immune response to something that’s not actually harmful.
This triggers the cell to release inflammatory chemicals, like histamine, which stimulate nerve cells, and cause blood vessels in the mucous membranes to swell and leak fluid.
Called the hygiene hypothesis, the idea is that when the immune system isn’t exposed to the familiar cast of microbes, it’ll keep itself busy mounting defenses against harmless substances, like pollen.
Another theory is that an immune system toughened up by a barrage of pathogens is less likely to overreact to allergens.
The body can even have an allergic reaction to itself causing auto-immune disorders, like multiple sclerosis, lupus, and type 1 diabetes.