“Premature greying of hair”的意思、由来-开放百科全书

Cause of greying is incompletely understood. It is a complex multi-factorial process mainly considered to be an interplay of nutritional, genetic and environmental factors.

Nutritional deficiencies like vitamin B12 deficiency, severe iron deficiency, chronic protein loss, copper deficiency are often found associated with premature greying of hairs. Other factors that have been incriminated are low serum ferritin, and low serum calcium and vitamin D3 levels.^[2]^[3]

Premature greying of hair has been observed with greater frequency among certain families, suggesting a familial predisposition for the condition. As hair pigmentation is a result of complex interaction between various genetic factors, it is thought that premature greying could be due to exhaustion of melanocyte's capability to produce hair pigmentation.^[1] Premature canities may occur alone as an autosomal dominant condition or in association with various autoimmune or premature aging syndromes. Down syndrome (trisomy 21) is characterized by features of accelerated aging including premature greying of hair and deficient DNA repair.^[4] Premature greying needs to be differentiated from various genetic hypomelanotic hair disorders.

Smoking is another factor that is considered to be related to premature greying of hair. Smoking results in generation of huge amount of reactive oxygen species leading to increased oxidative stress culminating into damage to melanin producing cells, melanocytes.^[5]^[6] Prolonged exposure to ultraviolet rays is considered to initiate similar processes in hair follicles resulting in premature greying of hair.

Management

Topical antiaging compounds that are currently under investigation include photoprotectors, such as cinnamidopropyltrimonium chloride and solid lipid nanoparticles as carriers for UV blockers, oral supplementation with l-cystine and l-methionine, and topical melatonin.^[6]

References

1. ^¹http://www.ijdvl.com/article.asp?issn=0378-6323;year=2013;volume=79;issue=5;spage=641;epage=653;aulast=Pandhi#ft4
2. ^{{cite journal|title=Epidemiological and Investigative Study of Premature Graying of Hair in Higher Secondary and Pre-University School Children|first1=Ramesh M|last1=Bhat|first2=Rashmi|last2=Sharma|first3=Anita C|last3=Pinto|first4=Sukumar|last4=Dandekeri|first5=Jacintha|last5=Martis|date=3 August 2017|publisher=|journal=International Journal of Trichology|volume=5|issue=1|pages=17–21 Central|doi=10.4103/0974-7753.114706|pmid=23960391|pmc=3746220}}
3. ^{{cite journal|title=Factors Associated with Premature Hair Graying in a Young Indian Population|first1=Swagata|last1=Chakrabarty|first2=Prafulla G|last2=Krishnappa|first3=Dinesh G|last3=Gowda|first4=Jyothi|last4=Hiremath|date=3 August 2017|publisher=|journal=International Journal of Trichology|volume=8|issue=1|pages=11–14 Central|doi=10.4103/0974-7753.179384|pmid=27127369|pmc=4830165}}
4. ^{{cite journal |vauthors=Raji NS, Rao KS |title=Trisomy 21 and accelerated aging: DNA-repair parameters in peripheral lymphocytes of Down's syndrome patients |journal=Mech. Ageing Dev. |volume=100 |issue=1 |pages=85–101 |date=January 1998 |pmid=9509398 |doi= |url=}}
5. ^{{cite journal|title=Smokers’ hair: Does smoking cause premature hair graying?|first1=Ayman A.|last1=Zayed|first2=Awni D.|last2=Shahait|first3=Musa N.|last3=Ayoub|first4=Al-Motassem|last4=Yousef|date=3 August 2017|publisher=|journal=Indian Dermatology Online Journal|volume=4|issue=2|pages=90–92 Central|doi=10.4103/2229-5178.110586|pmid=23741662|pmc=3673399}}
6. ^¹{{cite journal|title=Oxidative Stress in Ageing of Hair|first=Ralph M|last=Trüeb|date=3 August 2017|publisher=|journal=International Journal of Trichology|volume=1|issue=1|pages=6–14 Central|doi=10.4103/0974-7753.51923|pmid=20805969|pmc=2929555}}