In the case of grass pollen, you'll have too much of it in your nose. So when grass pollen enters, it'll bind with this allergy protein, which releases a lot of chemicals and most people are familiar with the one, histamine. It also induces a lot of itching, eyes, nose, sneezing. And if you breathe it down into the chest, you very easily get asthma.
If you breathe in a great deal or more commonly, you take something by mouth, a medicine or get an injection, you can have a whole body reaction that really can be a life-threatening reaction, we call anaphylaxis.
ANNOUNCER: There are two main types of allergy-seasonal, and chronic or year-round allergies.
BETH CORN, MD: Hay fever is usually what presents in the springtime. And the reason that it has this name is because about 150 years ago, the hay harvesting season was in the spring, and so people thought that these symptoms were from hay. But in actuality, the symptoms are caused by grass and trees.
MARJORIE SLANKARD, MD: In addition there are year-round factors such as house dust mites, cat and dog dander, and also molds, which can increase in seasons, but can be present indoors all year round.
GILLIAN SHEPHERD, MD: Commonly people have allergies as a child and by the time, usually with puberty, the allergies will settle down. And then suddenly pop back again 20's, 30's, 40's. Although it's less common, we all have patients in their 70's and 80's who will develop allergy for the first time.
ANNOUNCER: Having allergic symptoms can greatly affect a person's quality of life.
BETH CORN, MD: I think people just tolerate the symptoms, and they just feel like "Well I'm somebody who just sneezes a lot. I'm just somebody who feels itchy a lot. I'm just somebody who clears my throat a lot."
