Before humans even came up with the word “allergy,” they observed how some people would get rashes, sneezes or become really, really sick from different things in their environment. Historians even noted how people in ancient civilizations talked about something called “plant fever,” which gave people runny noses.
On the way to discovering allergies, scientists first had to learn about the immune system, which helps protect the body from invaders, or things like bacteria and viruses. These invaders are called antigens and when they get into your system, your body gets ready to react, releasing something called antibodies to help defend you. The antibodies will also recognize if they’ve come across an invader before. That way they know what to attack in the future. Allergens include things like shellfish, dust, eggs, pollen and insect venom.
Early in the last century, the Austrian scientist Clemens von Pirquet realized that the immune system isn’t there to just protect us. This was actually a very big and new idea at the time, which was about a hundred years ago. Pirquet helped us understand that while antibodies are on the lookout for invaders like bacteria, sometimes they mistake an allergen as something that is harmful.
The immune system is just trying to do its job, but it isn’t perfect. It can sometimes bring on serious reactions in the body. When people are having an allergic reaction, they will often get a runny nose, itchy eyes, sneeze a lot, but they have more serious reactions like trouble breathing and throwing up.
Pirquet was actually the scientist who helped coin the term “allergy” and he used it to talk about how our immune system can react and respond to invaders in different ways. He helped us understand that the immune system can sometimes set off false alarms.
As is often the case with curious science questions, we can also look at this one from another angle. Doctors are discovering different allergies in different people all the time. I talked to my friend Jennifer Robinson about it. She’s a clinical associate professor of pharmacy at Washington State University.
Today we can discover what a person is allergic to with a simple test. Robinson said doctors will often make a tiny scratch on the surface of the person’s skin and inject a little bit of the allergen. Then, they will look for a little redness or swelling near the injection site to see how the body reacts. They are also prepared to respond, just in case the patient gets really sick.
If you do have allergies, doctors may prescribe medicine, have you use a device called an EpiPen, or have you avoid the allergens entirely. We can help make sure our friends with allergies stay safe by keeping allergens away from them, too.
Asked by Zion, aged 8.