Emma Miller is one of an estimated 30% of children with an allergy. One in five American adults has reoccurring allergies.

And here's why:
"These are the cells which are responsible for allergic reaction," says Inder Verma, Ph. D. of the Salk Institute.

Called mast cells, they live in your blood stream. When you're exposed to an allergen like peanuts or pollen, it starts a chain reaction of symptoms that range from mild irritation like watery eyes or nose, to shock and even death.

"Like a peanut, or a cat hair or a pollen which causes hay fever, comes along in our blood stream, it finds those mast cells and activates them," says Verma.

When activated, these little blue sacks inside those cells blasts your bloodstream with histamine.

"They have little sacs in them which are filled up with small chemicals including histamine," says Verma.

Histamine can make you feel miserable.

But, Salk Institute researchers Inder Verma and Kotaro Suzuki discovered a molecule that keeps the histamine in those little blue sacs and out of your blood to stop an allergic reaction before it starts.

"Prevent the reaction, to not allow the histamine to come out. And that we think in some ways can be more useful, because we actually block it from it's very roots," says Verma.

A scientific discovery that may one day blossom into a cure for allergies.