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Photic Sneeze Reflex or ACHOO Syndrome

Author: Thomas C. Weiss : Contact: Disabled World

Published: 2014-06-27

Synopsis and Key Points:

Information regarding ACHOO syndrome, a condition that causes a person to sneeze when they are suddenly exposed to bright light.

Main Digest

Photic Sneeze Reflex or, 'Autosomal Dominant Compelling Helioophthalmic Outburst (ACHOO) Syndrome, is a genetic dominant disorder resulting in uncontrollable sneezing in response to a number of stimuli such as cold air, bright lights, or strong flavors. Approximately 18-35% of the population is affected by ACHOO. Unfortunately, the exact mechanisms behind the syndrome are not well understood.

ACHOO is a dominant hereditary trait, one that causes a person to sneeze - possibly many times in a row, when they are suddenly exposed to bright light. The first mention of this syndrome is most likely in the later work attributed to Aristotle.

Causes of ACHOO

The probable cause of ACHOO is a congenital, 'malfunction,' in nerve signals in the fifth cranial nerve called the, 'trigeminal,' nerve, which is seemingly responsible for sneezes. Researchers suggest that some people have an association between this particular nerve and the nerve that transmits visual impulses to their brain. Over-stimulation of their optic nerve triggers their trigeminal nerve and apparently causes the resulting photic sneeze reflex.

The sneeze reflex may also be caused by sudden inhalation of cold air, or exposure to strong flavors. What this implies is that an over-stimulation of any nerve close to the trigeminal nerve might cause the sneeze reflex.

Chart presenting facts about ACHOO syndrome
Chart presenting facts about ACHOO syndrome

The fullness of a person's stomach is another example of a stimulus that causes uncontrollable sneezing that might be linked to ACHOO syndrome. People who exhibit this symptom experience uncontrollable bouts of 2 to 15 sneezes promptly after consuming large meals that completely fill their stomachs. The, 'satiation,' reflex happens independently of the person's choice of foods and it is not something that is believed to be any kind of allergic reaction.

There is a certain amount of debate concerning the actual cause and mechanism of the sneezing bouts people experience in relation to ACHOO syndrome. Sneezing happens in response to irritation in a person's nasal cavity. The most plain difference between an average sneeze and an ACHOO syndrome related one is the stimulus. Average sneezes happen because of an irritation in a person's nasal cavity. ACHOO sneezes may be the result of a large number of stimuli.

Dangers Associated with ACHOO Syndrome

A bout of sneezing while driving a vehicle may cause the driver to lose control of their vehicle and result in damages to the driver, other people, vehicles, as well as things in the area. ACHOO syndrome presents a considerable risk to aircraft pilots because of the presence of the bright sun and the exact reactions required to safely fly an airplane.

Uncontrollable bouts of sneezing are common in people under propofol sedation who undergo periocular injection. A sneeze by a person who is sedated many times happens upon insertion of a needle into, or around, the person's eye. The violent and uncontrollable movement of the head during a reflexive sneeze may potentially cause damage within the person's eye if the needle is not removed before the sneeze happens.

Chart presenting dangers of ACHOO and driving
Chart presenting dangers of ACHOO and driving

At this time there is no definitive way to cure the sneezing bouts brought on by ACHOO syndrome. Photic sneezing may be fought by shielding an affected person's eyes with sunglasses or hats. There are a number of minor things a person with ACHOO syndrome can do, such as placing a finger horizontally below their nose, or holding their nose closed when they feel the stirrings of a sneeze coming on.

There is currently no definitive way to cure the sneezing fits brought on by ACHOO syndrome. Photic sneezing can be combated by shielding ones eyes with hats or sunglasses. There are many remedial fixes for sneezing, such as placing a finger horizontally below the nose or holding the nose closed when the beginnings of a sneeze are felt.

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