Question and Answer
What are allergies?
How do allergies work?
What is pollen?
Why are some allergies seasonal and others year-round?
Who gets allergies?
Yet respiratory allergens such as pollen from grass, trees, or weeds are not dangerous. They're a normal part of our world. So we don't grow up making a habit of avoiding them. That's what makes allergies difficult to treat.
A: When you breathe in something like pollen, some of it works its way into the lining of your nose, where it encounters your immune system. The first time this happens, your immune system decides the pollen is dangerous, and forms a small amount of antibody to it. That's all that happens. No sneezing, no runny nose, no symptoms.But the second time you breath in the pollen, and every time thereafter, something different happens. Your immune system remembers the pollen and forms lots of antibody. The antibody stimulated cells located in your nose, eyes, throat, and lungs, named mast cells or basophils, to release a substance called histamine. Histamine, in turn, makes your tissues secrete fluids and become irritated. The result is a runny nose, nasal congestion, sneezing, watery eyes, and itching of the nose, ears, and throat. Your body is trying to expel the pollen you breathed in.
A: Pollen is the male fertilizing agent of plants. To the naked eye, it looks like a fine grain or a particle of dust. For plants to reproduce, they must transfer it from one plant to another. They rely on the wind to sweep pollen into the air and onto female reproductive structures of other plants, a process known as pollination. Unfortunately, we breathe the same pollen-filled air. The pollens that commonly create allergies come from three groups of plants: trees, including common varieties like oak and birch; grasses; and the biggest culprit, ragweed, which causes nearly 75% of all allergies.Q: Why are some allergies seasonal and others year-round?
A: If you have allergies that change with the seasons, they're probably caused by pollen, because different plants pollinate at different times of the year.Trees release pollen in the spring. Grasses do so in late spring and early summer. Ragweed pollinates in the late summer until the first frost of fall. The exact timing for these three allergy seasons depends on where you live.
Since your allergy symptoms change with the amount of pollen in the air, you'll have more difficulty on windy days, since more pollen is swept into the air. Rain, on the other hand, tends to clear the air. You'll find these times more comfortable.
The full medical term for allergies caused by pollen is seasonal allergic rhinitis; "seasonal" refers to changing with the seasons; rhinitis comes from the ancient Greek word for the nose. But the most common name for these allergies is hay fever. As you've learned, hay has nothing to do with these allergies, and allergies don't cause fevers. The expression comes from the English doctor, Dr. John Bostock, who coined it in 1828. He suffered from severe summer allergies and found it interesting that his problem occurred during the British haying season.
If you have allergies that bother you year-round, they most likely stem from things that don't change with the seasons. The most common include household dust mites, animal dander from pets, feathers, and mold spores. We call these perennial allergens. More often than not, people are allergic to more than one thing. So you may find your symptoms changing more than once each year. For example, you may have difficulty with pollens, but get no relief in the winter due to dust. Or you may have no problem in cold weather, but suffer during the eight months pollination occurs. No two people are exactly the same.
A: Like many problems of the immune system, we don't know, as yet, how people develop allergies. We do know that approximately 50 million Americans suffer from allergy symptoms; and that their sensitivity often starts in childhood or young adulthood. We also know that the tendency to develop allergies is inherited.