Difference between revisions 13149156 and 13171297 on enwiki

< previous diff
next diff >
Photic sneeze reflex
'''Photic sneeze reflex''' (also whimsically called '''ACHOO''', a [[backronym]] for ''Autosomal dominant Compelling Helio-Ophthalmic Outburst'') is a medical condition by which people exposed to bright light involuntarily [[sneeze]]. It has been suggested that the photic sneeze reflex occurs only after someone has been adapted to the dark for at least five minutes, although this is not certain, and is not uniform amongst people with the photic sneeze reflex. The condition occurs in one-sixth to one-quarter of [[human]]s, with more common occurrence in [[Caucasian race|Caucasians]] than other human [[race]]s. The trait is passed along [[genetic]]ally, with a 50 percent chance of inheritance.  ⏎
⏎
The first mention of the phenomenon is probably in the works of [[Aristotle]] (book XXXIII).

The probable cause is a congenital malfunction in [[nerve]] signals in the [[trigeminal nerve]] [[cell nucleus|nucleus]]. The fifth [[cranial nerve]], called the trigeminal nerve, is apparently responsible for sneezes. Research suggests  that some people have an association between this nerve and the nerve that transmits visual impulses to the brain. Overstimulation of the [[optic nerve]] triggers the trigeminal nerve, and this causes the photic sneeze reflex. Another theory suggests that tears leaking into the nose through the [[nasolacrimal duct]] are a cause of the photic sneeze reflex. The speed of the reflex seems to favour the first theory, as it happens much too quickly for tears to be generated and drain into the nose.

The photic sneeze reflex is considered a risk factor to [[combat]] pilots: people suffering from photic sneeze reflex may not fly combat [[aircraft]].

==References==
⏎
⏎
* Semes LP, Amos JF, Waterbor JW. "The Photic Sneeze Response: Descriptive Report of a Clinic Population." ''Journal of American Optometry Association'' June 1995, 66(6): pp. 372&ndash;377 [On-line], Available: [http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m_d]
⏎
⏎
* Deshmukh, N. "Sneezing photic response to bright light. Is it a cause of accidents?" ''The Guthrie Journal'', 1995, 64(3): 104&ndash;105 
⏎
⏎
* Breitenbach, R.A, "The Photic Sneeze Reflex as a Risk Factor to Combat Pilots." ''Military Medicine'', 158, December 1993: 806&ndash;809, Abstract: [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8108024]⏎
<!-- Old link, no longer valid - http://www.cathouse.org/medical/photic_sneeze.html -->

==External links==
*{{OMIM|100820}}
*[http://www.madsci.org/posts/archives/aug97/865380242.Me.r.html MadSci article on the photic sneeze reflex]
*[http://www.sciam.com/askexpert_question.cfm?articleID=0004BA86-E838-1DD3-A838809EC588F2D7 Scientific American notes on the photic sneeze reflex]
*[http://loin.free.fr/john/medical_articles.html Annotated biography on medical journals on the photic sneeze reflex]
*[http://www.straightdope.com/classics/a2_303.html The Straight Dope on photic sneeze reflex]⏎
*{{OMIM|100820}}

[[Category:Reflexes]]

[[de:Photischer Niesreflex]]
[[es:Reflejo de estornudo por luz brillante]]