Question: A friend of mine claims to only sneeze when she’s exposed to bright sunlight. As someone with seasonal allergies, I understand how pollen can cause people to sneeze, but why would bright light make my friend sneeze?
Answer: Sneezing is an involuntary reflex caused by many different things. As you noted, during the spring or fall months people with seasonal allergies sneeze in response to pollen or spores. The sneezing is your body’s attempt to clear out the allergens irritating the lining of your nose and throat.
Your friend’s claim, that bright sunlight can cause sneezing, is actually a documented medical syndrome. The syndrome is called ACHOO –- and no, I am not making this up. It stands for “Autosomal-dominant Compelling Helio-Ophthalmic Outburst,” also called photic sneezing. If you ever start to sneeze and it gets “stuck,” try looking toward a light source to see if it helps you finish the sneeze.
Sneezing from bright lights is a genetic condition that affects about 20 percent of the population. The term “autosomal-dominant” means that if one parent has the gene, each child has a 50 percent chance of inheriting it. The exact mechanism by which bright light brings on sneezing in certain people is not fully understood.
Aside from allergies, illness and bright lights, a number of other things reportedly cause sneezing. Some people say they sneeze when they pluck their eyebrows. Others sneeze when their stomach is full, which is referred to as stomach sneeze reflex. Still others sneeze when their stomach is empty and they feel nauseated. The nausea seems to be somehow relieved by sneezing. Physicians and scientists do not fully understand unusual sneezing triggers, and since the matter seems to be of no medical consequence, we are not likely to bother figuring it out.
Interestingly, the practice of saying “God bless you” to someone who has just sneezed began during the 6th Century bubonic plague epidemic. Sneezing took on troubling connotations since it was one of the earliest symptoms of infection with the plague.
Sneezing is also an early symptom for many other bacterial infections as well as viral illnesses such as the cold or the flu. If you develop more serious symptoms such as fever or body aches along with your sneezing, you should seek medical attention. Normally, however, a few isolated sneezes are not cause for alarm. Nearly anything can irritate the throat and nose even if you are not allergic to it, including excessive pollen, smoke, pepper and dust.
Sneezing, which employs several muscle groups from your abdomen to your throat, is a very powerful “outburst” and a very effective way of spreading germs. During an ordinary sneeze, saliva can fly up to ten feet at roughly 75 miles per hour. Even if you are not feeling sick, you should always cover your nose and mouth when you sneeze.
