[MUSIC]
[PIANO MUSIC]
(sneezing) (coughing)
(blowing nose) (sneezing)
(groaning) (sneezing)
(coughing) (groaning)
Ralph Waldo Emerson wrote that “Earth laughs in flowers”
"Ha ha ha ha"
Well, you know what? I don’t think it’s funny. If you’re like me, the coming of
spring signals one thing: allergies.
[MUSIC]
I mean seriously, how much crud can my head really hold? It’s like Hermione’s purse
up in there.
Of course it’s not really fair to blame flowers for most seasonal allergies. While
most plants do keep their pollen-covered private parts right out there in the open, flower
pollen is usually too heavy to go airborne, instead they get bees and other pollinators
to help them do the fertilization deed.
[FUNKY MUSIC]
It’s mainly trees and grasses that let their genetic material loose on the wind, and they
don’t mess around. I mean really?! Is that necessary? If one
tree needs that much pollen to reproduce, maybe evolution is trying to tell you something.
That’s all I’m saying.
Maybe this was a mistake… By my immune system! Allergic reactions are
the result of our immune system going haywire, and doing battle with completely and totally
harmless stuff like pollen, dust, or pet dander, because it clearly has nothing better to do.
Your body enlists several types of antibodies in its immune army. Most are sent out to fight
different invaders like viruses and bacteria, but this one, IgE, seems to have just one
purpose: making us miserable a few times a year… I mean mediating our body’s response
to allergens.
When we are first exposed to an allergen, we don’t have much of a reaction… on the
outside. But inside our bodies, it’s different. A special cell in our immune system vacuums
up foreign antigens and presents them to other cells, like “Hey, check this out, this doesn’t
belong here.” Mr. T cell sniffs it out, and says, “I pity the fool who try and invade
my mucous membrane”, sending out a chemical signal that turns on our B cell antibody factories
which pump out IgE proteins that bind specifically to the pollen, cat hair, bee venom, whatever.
The IgEs latch on to these mast cells, where they wait quietly for the NEXT time the allergen
shows up, and when that happens, BAM, the mast cells start pumping out a chemical called
histamine. You might know it from all the anti-histamines you take to beg it, at any
cost, to please stop doing its histamine thing.
Histamine causes blood vessels in your nose to dilate and become leaky, it stimulates
nerves to make you sneeze, and even increases inflammation, giving you that nice red-nosed
look to set off those bloodshot eyes. What’s weird is that in developed countries,
allergies seem to be getting more common. In the US, food allergies in children have
increased by 50% since 1997, and environmental allergies are estimated to affect up to one
in three people at any time. So, what gives?
Allergies do seem to have a genetic basis. Parents with allergies are more likely to
have children with allergies, although they’re not necessarily to the same thing, but identical
twins are likely to share specific allergies.
Many scientists think that perhaps we’re living too clean, that our hygienic lifestyle
doesn’t train our immune systems correctly from a young age. Many allergies and autoimmune
diseases are less common in the developing world, and as nations get richer, they get
more allergic. Maybe playing in the mud a bit more could keep us from sneezing later
in life.
Some researchers have found that increasing exposure to an antigen over time, usually
in drops placed under the tongue, can desensitize the body from reacting. And in 2013, Johns
Hopkins researchers pinpointed a pathway involving the protein TGF-beta as a possible culprit
for this whole sneezy mess.
Our microbiome might have something to do with it too. A small study done by the BBC
found fewer species of bacteria living on folks with allergies than without, and researchers
have seen that when other parts of the immune system were exposed to and fought off bacteria,
it silenced the part of the immune system that activates IgE. In another study, mice
given certain bacteria were cured of a peanut allergy.
It’s likely that, like most things in medicine, allergies are likely due to more than one
cause, our hygiene, our environment, even our changing lifestyles. But one thing’s
for sure.
Snot fun.
(laughing)
Stay curious.