Wednesday, March 23, 2016

Sneezing Up A Storm

Wednesday, March 23, 2016
2:28 pm

Every year, around the first week of March, springtime allergies hit me harder than a bottle of caffeine pills. For the majority of the winter, I'm totally fine, and then suddenly, my eyes are the wettest they've been since stupidly eating some absurdly hot chili pepper in Indonesia. Ten to thirty percent of the world has seasonal allergies, and I am one of those people. In fact, I almost sneezed as I was just typing that sentence. Now, I'll be yearning for a sneeze for the rest of the day.

I'm allergic to cats (though we still had one) and mildly allergic to dogs (though I love my dog and wouldn't give him up for the world), but I'm incredibly allergic to horses. Put me on a horse, and I'll sneeze, cry, and punch my nose like you wouldn't believe. I love riding horses too - I just need to take a ton of allergy medicine well beforehand - it takes weeks for the medicine to fully get into my system and have a noticeable effect on my horse allergies.

Luckily for me, my allergies are just an inconvenience. I do not have life-threatening allergic reactions to peanuts or bee stings. But even though those allergies are much more severe, the basic mechanism behind all allergic reactions is the same. So before we get specifically into hay fever, let's talk about how allergic reactions work.

Allergic reactions occur when the body's immune system identifies a normally harmless substance as a hazard to the body's health. When a person is exposed to an allergen for the very first time, they generally do not experience a severe allergic reaction. However, some individuals develop antibodies to these allergens, and the next time an allergen enters the body, the antibodies produce "histamines," which then act on various areas of the body and create different types of allergic reactions. Some allergies, like hay fever, are relatively harmless in the grand scheme of things, while others, like nut allergies, can cause the body to experience a rapid drop in blood pressure and go into anaphylactic shock. In these cases, a shot of epinephrine (an Epi-Pen) must be administered immediately, as the sufferer could die in as little as 15 minutes after being exposed to the allergen. Allergies are not just found in humans; even man's best friend can go into anaphylactic shock if they are exposed to a particular allergen.

A scanning electron microscope image of pollen grains from sunflower, morning glory, prairie hollyhock, oriental lily, evening primrose, and castor bean. Credit: Dartmouth College

Hay fever is caused by the body's immune response to pollen. The severity of hay fever symptoms varies among different people, but it is extremely rare for a person to go into anaphylactic shock because they have been exposed to pollen. That's a good thing, because pollen is pretty much everywhere!

Pollen itself is a powdery substance composed of individual pollen grains, or microgametophytes. Though we usually don't think of plants as having a certain sex, pollen grains produce sperm cells, and therefore are the "male" part of the plant as a whole. This is why bees are so important... they allow plants to reproduce by depositing the pollen grains on the female receptacles, or megagametophytes. In a flower, the microgametophytes are found on the stamen, while the megagametophytes are found on the stigma. So ladies, next time you get ambushed by hay fever, find one of your guy friends and blame him and all his microgametophyte friends for making you sneeze!

Credit: American Museum of Natural History

In the springtime, trees are the most common source of pollen. Particularly notorious trees in my neck of the woods include Cedar and Maple, especially Maple. In summer, grasses are the most prevalent source of pollen, and by autumn, weeds are the main offenders. Although pollen decreases in the winter, some people are still allergic to mold and dust, and indoor air is generally dirtier than outdoor air. Allergies are generally worst on breezy days when lots of pollen has been knocked off of plants, but if it is too windy, cleaner air from the upper atmosphere will get mixed down and pollen concentrations will decrease. Pollen concentrations are usually lowest if it is raining cats and dogs, as raindrops capture pollen and other aerosols and remove them from the atmosphere.

There are a variety of medications you can use to mitigate hay fever. Many are "antihistamines," which reduce the amount of histamines your body produces so you don't have as much of an allergic reaction. Some, like Benadryl, cause drowsiness, while others, like Claritin, keep you perfectly awake. However, in recent years, prescription nasal sprays such as Flonase have become available over-the-counter, and I've had better success with these. These are steroids instead of antihistamines, and are stronger and longer lasting than most antihistamines. If springtime has got you feeling under the weather, get a nasal spray, and you'll be back to feeling better in no time.

Thanks for reading!

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