{{Infobox medical condition (new) | name = Onycholysis | synonyms = | image = Onycholysis left hand 34yo male ring and little fingers non-fungal.jpg | caption = Left hand onycholysis: ring and little fingers affected | pronounce = {{IPAc-en|ˌ|ɒ|n|ᵻ|ˈ|k|ɒ|l|ɪ|s|ɪ|s}} | field = | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }} '''Onycholysis''' is a common medical condition characterized by the painless detachment of the nail from the nail bed, usually starting at the tip and/or sides.<ref>{{cite book|last=Freedberg|year=2003|title=Fitzpatrick's Dermatology in General Medicine|edition=6th|publisher=McGraw-Hill|isbn=978-0-07-138076-8|pages=660|display-authors=etal}}</ref> On the hands, it occurs particularly on the ring finger but can occur on any of the fingernails. It may also happen to toenails.

Onycholysis can occur in many conditions, including psoriasis.<ref>{{cite book|author=Dennis, Mark|author2=Bowen, William Talbot|author3=Cho, Lucy|chapter=Onycholysis (Plummer's nail)|chapter-url=https://books.google.com/books?id=FIV-NYPRCzEC&pg=PA542|title=Mechanisms of Clinical Signs|year=2012|publisher=Elsevier|page=542|isbn=978-0729540759}}</ref> In thyrotoxicosis, it is thought to be due to sympathetic overactivity.<ref>{{cite book|last=Talley&O'Connor|year=2006|title=Clinical Examination A Systematic Guide to Physical Diagnosis|edition=5th|publisher=Elsevier|isbn=978-0-7295-3762-9|pages=262}}</ref> It may also be seen in infections or trauma.<ref>{{cite book|last=Weber&Kelley|year=2010|title=Health Assessment in Nursing|edition=4th|publisher=Wolters Kluwer Health and Lippincott, Williams & Wilkins|isbn=978-0-7817-8160-2|pages=[https://archive.org/details/healthassessment0004webe/page/193 193]|url=https://archive.org/details/healthassessment0004webe/page/193}}</ref>

==Causes== * Unknown * Frequent hand washing as well as exposure to soaps and detergents can lead to brittle nail syndrome which manifests as Onychorrhexis and Onychoschizia) * Trauma excessive manicuring * Trauma which manifests as Onychorrhexis * Tumor which manifests as Onychorrhexis or Onychopapilloma * Infection: especially fungal * Skin disease: psoriasis, dermatitis * Impaired peripheral circulation, e.g. Raynaud's syndrome * Systemic disease: hyperthyroidism, hypothyroidism, reactive arthritis, porphyria cutanea tarda * Reaction to detergents (e.g. washing dishes with bare hands, using detergent-based shampoos or soaps).<ref>{{Cite journal|last1=Mayon-White|first1=R. T.|last2=Hodgson|first2=G.|date=1971-08-07|title=Acute onychia and onycholysis due to an enzyme detergent.|journal=Br Med J|language=en|volume=3|issue=5770|pages=352|doi=10.1136/bmj.3.5770.352|issn=0007-1447|pmid=5558190|pmc=1798590}}</ref><ref>{{Cite journal|last1=Al-Kathiri|first1=Lutfi|last2=Al-Asmaili|first2=Abla|date=2016|title=Diclofenac-Induced Photo-Onycholysis|journal=Oman Medical Journal|volume=31|issue=1|pages=65–68|doi=10.5001/omj.2016.12|issn=1999-768X|pmc=4720947|pmid=26816569}}</ref><ref>{{Cite journal|last1=Alevizos|first1=Alevizos|last2=Gregoriou|first2=Stamatis|last3=Larios|first3=George|last4=Rigopoulos|first4=Dimitris|date=2008-02-01|title=Acute and Chronic Paronychia|url=https://www.aafp.org/afp/2008/0201/p339.html|journal=American Family Physician|language=en|volume=77|issue=3|pages=339–346|pmid=18297959|issn=0002-838X}}</ref> * Patients with hepatocellular dysfunction may develop hair-thinning or hair loss and nail changes such as clubbing, leukonychia (whitening), or onycholysis, affecting the nails of the hands and feet.<ref>{{cite journal|first1= Ribhi|last1= Hazin|first2= Tarek I. Abu-Rajab|last2= Tamimi|first3= Jamil Y.|last3= Abuzetun|first4= Nizar N.|last4= Zein|title= Recognizing and treating cutaneous signs of liver disease|url= http://www.ccjm.org/content/76/10/599|journal= Cleveland Clinic Journal of Medicine|date= October 2009|issn= 0891-1150|pages= 599–606|volume= 76|issue= 10|doi= 10.3949/ccjm.76A.08113|pmid=19797460|doi-access= free}}</ref> * Onychomycosis (tinea) * It is common in ballet dancers<ref>{{cite web |last1=Shah |first1=Selina |title=Pointe shoes complicate biomechanics of ballet|url=https://lermagazine.com/article/pointe-shoes-complicate-biomechanics-of-balle |website=Lower Extremity Review Magazine |date=April 2010}}</ref> * Chemotherapy (cytotoxic agents like taxanes, vinca alkaloids and others) * Chronic Renal Failure<ref name="Niema Aicha Salim Fatima Zahra p. ">{{cite journal | last=Niema | first=Aqil | last2=Aicha | first2=Nassiri | last3=Salim | first3=Gallouj | last4=Fatima Zahra | first4=Mernissi | title=Nail Disorders in Patients with Chronic Renal Failure | journal=Journal of Dermatology Research and Therapy | publisher=ClinMed International Library | volume=5 | issue=1 | date=2019-06-30 | issn=2469-5750 | url=https://clinmedjournals.org/articles/ijdrt/journal-of-dermatology-research-and-therapy-ijdrt-5-065.php?jid=ijdrt | page=}}</ref>

==Treatment== Most instances of onycholysis without a clear cause will heal spontaneously within a few weeks. The most commonly recommended treatment is to keep the nail dry as much as possible and allow the nail to slowly reattach. Trimming away as much loose nail as can be done comfortably will prevent the nail from being pried upwards. Cleaning under the nail is not recommended as this only serves to separate the nail further. Bandages are also to be avoided.<ref name="aoc">{{cite web|url=http://www.aocd.org/?page=Onycholysis|title=Onycholysis|publisher=American Osteopathic College of Dermatology|access-date=29 December 2016}}</ref> When kept dry and away from further trauma, the nail will reattach from the base upward (i.e., from proximal to distal). The aim of treatment is also to eliminate onychomycosis that is a major cause of onycholysis. Antifungals like terbinafin and itraconazole in the form of oral pills should be given for 6 to 8 weeks.<ref name=aoc/>

If the underlying cause of the condition is not found and the nail continues to detach despite conservative treatment, the nail bed may begin to form a granular layer of abnormal cells on its surface. After six months of detachment, this layer is likely to prevent the adhesion of any new nail tissue, possibly leading to permanent deformity.<ref>{{cite web|url=http://www.nailsmag.com/article/91567/the-nail-doctor-onycholysis-or-nail-separation-has-different-varieties|title=The Nail Doctor: Onycholysis, or Nail Separation, Has Different Varieties|author=Richard K. Scherr|date=1 December 1997|publisher=Nails Magazine}}</ref>

== Asymmetric Gait Nail Unit Syndrome (AGNUS) == Asymmetric Gait Nail Unit Syndrome (AGNUS) is a specific form of trauma-induced lateral (inner side of the nail) onycholysis affecting the great toenails. First described by dermatologist Nardo Zaias, AGNUS mimics the clinical appearance of distal subungual onychomycosis (nail fungus) but is entirely fungus-free.<ref name="Zaias2015">{{cite journal |last1=Zaias |first1=N. |last2=Escovar |first2=S. X. |last3=Zaiac |first3=M. N. |title=Finger and toenail onycholysis |journal=Journal of the European Academy of Dermatology and Venereology |date=2015 |volume=29 |issue=5 |pages=848–853 |doi=10.1111/jdv.12862 |pmid=25512134}}</ref> The condition is caused by chronic, repetitive micro-trauma resulting from asymmetric biomechanics during ambulation, for example in patients with hallux valgus.<ref name="Zaias2014">{{cite journal |last1=Zaias |first1=N. |last2=Rebell |first2=G. |last3=Casal |first3=G. |last4=Alvarez |first4=J. |title=Asymmetric gait nail unit syndrome (AGNUS), the main cause of toe nail onycholysis |journal=Skinmed |date=2014 |volume=12 |issue=3 |pages=161–163 |pmid=25335350}}</ref> This mechanical stress typically occurs when an asymmetric gait causes one or both great toenails to repeatedly strike the inside of closed footwear.<ref name="Zaias2014">{{cite journal |last1=Zaias |first1=N. |last2=Rebell |first2=G. |last3=Casal |first3=G. |last4=Alvarez |first4=J. |title=Asymmetric gait nail unit syndrome (AGNUS), the main cause of toe nail onycholysis |journal=Skinmed |date=2014 |volume=12 |issue=3 |pages=161–163 |pmid=25335350}}</ref> Clinical features include asymmetric or symmetric lateral and distal lifting of the nail plate, often accompanied by subungual hyperkeratosis. Diagnosis is confirmed by demonstrating the absence of fungal elements through potassium hydroxide (KOH) preparation, histopathology, or fungal culture, combined with a physical evaluation of the patient's gait and footwear.

==Etymology== The word ''onycholysis'' comes from ''onycho-'', from Ancient Greek ὄνυξ ''ónuks'' 'nail', and Ancient Greek λύσις ''lúsis'' 'lysis/disintegration'.<ref>{{Cite web |last=Services |first=ProZ com Translation |title=lusis {{!}} Greek (Ancient) to English {{!}} Poetry & Literature |url=https://www.proz.com/kudoz/greek-ancient-to-english/poetry-literature/644733-lusis.html |access-date=2022-10-08 |website=ProZ.com {{!}} Freelance translators and interpreters |language=en}}</ref>

==See also== * List of cutaneous conditions *

==References== {{Reflist}}

==External links== {{Medical resources | DiseasesDB = 9236 | ICD10 = {{ICD10|L|60|1|l}} | ICD9 = {{ICD9|703.8}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = D054039 }}

Category:Conditions of the skin appendages