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A sneeze is a natural reflex when something irritates the inside of our nose. It also happens when we come out into the sun from a dark room. The problem has not yet been solved scientifically, but according to an American neurologist, unraveling the mystery could help in treating epilepsy.
- Sneezing as a reaction to sudden exposure to sunlight affects up to 30 percent. people
- Why is this happening? It is not known. There is a lack of thorough research, because there are no people willing to spend money on it
- And this reflex – as prof. Louis Ptáček – can be very dangerous under certain circumstances
- More current information can be found on the Onet homepage.
Sun allergy?
Do you ever sneeze right after you go out in the sun? Contrary to appearances, it is not such a rare condition. It is estimated that this reflex affects 10-35 percent. society. Sneezes can be both single and multiple. This harmless disorder was reportedly described by the Greek philosopher Aristotle of the XNUMXth century BC
Scientific name ACHOO: Autosomal Dominant Compelling Helio-Ophthalmic Outburst Syndrome gained in 1954 when it was described in the medical literature. The acronym ACHOO was not coined by accident, as it is a phonetic representation of a sneeze in English. «Ahoo» is simply «apsik».
– This is not a disease – says prof. Louis Ptáček, neuroscientist and geneticist at the University of California, San Francisco, interviewed by NewHour. – Some people find it annoying, but there are some who like it to some extent. They say the sun lets them sneeze.
The disorder is a sudden sneeze or series of sneezes in a person who – being in a darkened place before – is suddenly exposed to sunlight. The trigger is sunlight, but sneezing can also be caused by light bulbs or a flash. The sneeze does not come immediately. There must be some – not exactly determined – time since the exit from the darker room, called the time of refraction.
This reflex is to some extent hereditary. It is more common in people who have a family history of it. A small group of scientists has dealt with the issue. They suspect the so-called autosomal dominant inheritance, i.e. one parent with this condition is enough to pass it on to the next generation.
Why are we sneezing?
A sneeze is a violent reflex designed to protect the nose, upper respiratory tract and lungs from infectious or irritating agents. It is estimated that we exhale up to 40 with each sneeze. microscopic droplets – at speeds from several dozen to over 100 km per hour.
“When we sneeze, the diaphragm contracts enormously,” explains Ptáček. – Dust or black pepper particles in the nose irritate the mucosa and lead to a sneezing reflex to prevent infection or irritation.
It can also be caused by a change in temperature or humidity, or by an unusual smell. Sneezing in this case is not associated with a runny nose, a feeling of heavy head (due to discharge in the sinuses) or other symptoms characteristic of infection or allergies.
Why do we sneeze in the sun?
But why has evolution made some of us sneeze when “attacked” by bright light? There are several theories. The most common assumption is that different nerve signals intersect: the trigeminal nerve (responsible for sensing sensations) senses facial sensations such as itchy nose, and the optic nerve constricts the pupils of the eye as light penetrates the retina.
However, there is a lack of serious research based on large groups to support any theory. Most of the analyzes of sneezing reflexes in the sun are based on studies of individual families or small groups of sneezers.
In 2010, a Swiss study found that 10 ‘sun sneezers’ were stimulated significantly more in the primary and secondary visual cortex – the areas of the brain that process visual information – at different wavelengths of light compared to those who did not. Information from the retina of the eye to the visual cortex is supplied by nerve fibers.
In turn, Spanish scientists in 2016 found that people with the solar sneeze reflex had thickened nerves in the cornea of the eye. The corneal innervation comes from the trigeminal nerve. Thirteen people participated in the study, but all of them were members of one family.
Sneezing in the sun can be dangerous
Prof. Ptáček works in genetics related to episodic disorders such as migraine headaches and epilepsy. His lab has been collecting sneeze reflex surveys for years, but he still lacks the funds for in-depth information analysis. This, in his opinion, is the main problem.
“Funding is hard to come by because reviewers don’t see it as a serious problem,” he says. – The money is spent on research into diseases such as Parkinson’s disease and multiple sclerosis.
In most cases, sneezes caused by sudden exposure to light are relatively harmless. But, as Ptáček points out, the “cumulative risk” of being temporarily blinded by light followed by sneezing and the associated eyes closure can be very dangerous in some situations.. This applies to, for example, acrobats on the rope, outfitters (standing farthest from the base) in baseball or military pilots. This phenomenon can also be dangerous for drivers leaving a dark tunnel at high speed.
Prof. Ptáček does not consider the issue unworthy of attention. Moreover, a closer look at this reflex may reveal more about other diseases. “If we knew one or more of the genes that trigger the sneezing reflex, I think that could teach us basic things about reflex disorders like epilepsy,” she said.
“Some of the most important advances in medicine have come from not focusing on medicine itself,” she adds.
We encourage you to listen to the latest episode of the RESET podcast. This time we devote it to ecology. How to be eco and not go crazy? How can we care for our planet on a daily basis? What and how to eat? You will hear about this and many other topics related to ecology in the new episode of our podcast.