Polyonychia
{{Short description|Presence of two or more finger/toe nails on a single finger/toe}}
{{Infobox medical condition
|name = Polyonychia
|synonyms = supernumerary nails of the fingers and toes
|image = File:Bulakenyo adolescent barefoot boy Jeepney passenger Syndactyly Webbed toes 03.jpg
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|caption = Polyonychia from congenital polysyndactyly
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|specialty = Medical genetics
|symptoms = Having two or more finger/toenails on a single digit
|complications = Social insecurity
|onset = Birth (congenital), post-traumatic (acquired)
|duration = Life-long (unless it's corrected)
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|treatment = Plastic surgery
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|prognosis = Good
|frequency = polydactyly: 1 in 500-1,000 live births{{citation needed|date= July 2023}} syndactyly: 1 in 2,500-3,000 births{{Cite web | url=https://emedicine.medscape.com/article/1244420-overview#:~:text=Syndactyly%20is%20the%20most%20common,in%202000%2D3000%20live%20births.&text=It%20is%20a%20failure%20of,eighth%20weeks%20of%20embryologic%20development. | title=Syndactyly: Practice Essentials, Etiology, Epidemiology | date=17 February 2022 }}
|deaths = None
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Polyonychia also known as supernumerary nails is a condition in which two or more nails grow in the same finger or toe.{{Cite web |title=Definition of polyonychia {{!}} Dictionary.com |url=https://www.dictionary.com/browse/polyonychia |access-date=2022-04-10 |website=www.dictionary.com |language=en}}
Signs and symptoms
The signs/symptoms of polyonychia are very easy to detect: two or more nails growing on the same finger or toe.
The nails can either be separate, small nails (micronychia) or one wide, almost complete nail, the digit affected could also be wider than normal
Causes
Polyonychia is generally caused by a congenital duplication of the distal phalange of the affected digit(s), this can be caused by congenital factors (sporadic without a genetic link) or by genetic factors (sporadic or familial with genetic link).
It can also be caused by polysyndactyly, which is characterized as one normal digit being connected/webbed (syndactyly) to an extra digit (polydactyly).
Polyonychia can also be acquired, such as after an accident that affected the nail bed causing it to split. This type of polyonychia is just referred to as "post-traumatic split nail" {{Cite journal |last1=Lade |first1=Nitin Ramchandra |last2=Jain |first2=Divya Bimit |last3=Singh |first3=Adarsh Lata |date=2012-06-01 |title=Post-traumatic acquired polyonychia: A rare occurrence |url=https://escholarship.org/uc/item/0755b6jk |journal=Dermatology Online Journal |language=en |volume=18 |issue=6 |page=10 |doi=10.5070/D30755b6jk|pmid=22747934 |url-access=subscription }}
Polyonychia's syndromic causes include:
- Isolated congenital onychodysplasia{{Cite web |last=RESERVED |first=INSERM US14-- ALL RIGHTS |title=Orphanet: Isolated congenital onychodysplasia |url=https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=79144 |access-date=2022-04-10 |website=www.orpha.net |language=en}}
Polyonychia's non-syndromic causes include:
- Polyphalangism (more specifically of the distal phalange){{Cite web |last=Knipe |first=Henry |title=Duplicated distal phalanx of great toe {{!}} Radiology Case {{!}} Radiopaedia.org |url=https://radiopaedia.org/cases/duplicated-distal-phalanx-of-great-toe |access-date=2022-04-10 |website=Radiopaedia |language=en-US}}
- Polysyndactyly
See also
References
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