We’ve had some gloomy days this winter. I probably need to dig my sunglasses out from under something. Today was the first bright day in sometime and as I was driving my kids to school, I said, “It’s so bright, it’s making my nose itch.” They laughed a little and then my little one said her friend at school always sneezes when she looks at the sun. Well, so do I. I remember coming out of the school where I used to teach and every day, I would sneeze twice on the way to my car. this is an actual condition, and though I’m not sure if it’s truly an allergy, I think it falls into the category, because the sneezing is a reaction to the bright light and sun.
Here is what wikipedia says:
“Photic sneeze reflex is an autosomal dominant hereditary trait which causes sneezing when exposed suddenly to bright light, possibly many times consecutively.”
Interestingly enough, about 25% of people experience this condition, depending which research you read (numbers vary from 10% to 34%) and it is considered to be an inherited condition, it’s an autosomal dominant trait, which means that if one parent has one copy of that gene, you have a 50 percent chance of being a sun sneezer. Neither of my kids sun sneeze, though, and neither does my husband, so I guess that they got their “non sun sneezing” gene from him.
Is there a purpose to this? I found an interesting piece on www.madsci.org that claims it is holdover from evolution when we used primarily through out noses to clear any irritants, and that now sneezing does little good unless we sneeze out of our noses, hmmmm. But again, what does bright light and the sun have to do with this? Back to the holdover evolution theory, it was beneficial when we came out of the dark dusty caves to clear our noses outside.
A hypothesis was proposed in the 1960’s that this “reflex is caused by a confusion of nerve signals in pathways” very close to one another. For most people, the pathways don’t interact, but for sun sneezers, one pathway stimulates the other. Other hypotheses exist; basically no one really knows for sure.