How do your allergies develop?


Boy with inhaler
Allergies affect millions of people worldwide, and the number is rising.

Worldwide, allergies are on the rise at an alarming rate. How do our bodies mistake otherwise harmless substances for potential dangers and cause the unpleasant, and sometimes even fatal, symptoms of allergy?

From the mother anxiously watching for signs of wheezing the first time her child eats peanut butter to the retiree’s sudden reaction to shellfish, allergies can strike at any point during our lives.

Hay fever affects 400 million individuals globally, with asthma affecting 300 million, food allergies between 200 and 250 million, and drug allergies affecting around 10 percent of the world’s population.

The World Allergy Organization (WAO) warn that “the prevalence of allergic diseases worldwide is rising dramatically in both developed and developing countries.”

Allergens, or molecules with the potential to cause allergy, are everywhere in our environment. They come in the form of tree pollen, food, mold, dust mites, snake or insect venom, and animals, such as cats, dogs, and cockroaches.

When the body mistakes one of these substances as a threat and reacts with an immune response, we develop an allergy. Nobody is born with allergies. Instead, the 50 million people in the United States who suffer from allergies developed these only once their immune systems came into contact with the culprit.

But how do our bodies mistake a friend for a foe? And what causes the symptoms that many are so familiar with?

Immune system surveillance

Allergy is defined as an inappropriate immune response to an…