Alopecia

In search of the “hair cycle clock”: a guided tour Auteur(s) / Author(s) PAUS Ralf ; FOITZIK Kerstin ; Résumé / Abstract The hair follicle, a unique characteristic of mammals, represents a stem cell-rich, prototypic neuroectodermal-mesodermal interaction system. This factory for pigmented epithelial fibers is unique in that it is the only organ in the mammalian body which, for its entire lifetime, undergoes cyclic transformations from stages of rapid growth (anagen) to apoptosis-driven regression (catagen) and back to anagen, via an interspersed period of relative quiescence (telogen). While it is undisputed that the biological “clock” that drives hair follicle cycling resides in the hair follicle itself, the molecular nature of the underlying oscillator system remains to be clarified. To meet this challenge is of profound general interest, since numerous key problems of modern biology can be studied exemplarily in this versatile model system. It is also clinically important, since the vast majority of patients with hair growth disorders suffers from an undesired alteration of hair follicle cycling. Here, we sketch basic background information and key concepts that one needs to keep in mind when exploring the enigmatic “hair cycle clock”(HCC), and summarize competing models of the HCC. We invite the reader on a very subjective guided tour, which focuses on our own trials, errors, and findings toward the distant goal of unravelling one of the most fascinating mysteries of biology: Why does the hair follicle cycle at all? How does it do it? What are the key players in the underlying molecular controls? Attempting to offer at least some meaningful answers, we share our prejudices and perspectives, and define crucial open questions. Revue / Journal Title Differentiation ISSN 0301-4681 Source / Source 2004, vol. 72, no9-10, pp. 489-511 [23 page(s) (article)] Langue / Language

Prevalence of male and female pattern hair loss in Maryborough.

Gan DC, Sinclair RD. Department of Dermatology, University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia. Maryborough, in central Victoria has an approximate population of 8000 and census data is well matched for Australia overall. Australia has compulsory voting and registration on the electoral roll. To determine the age-related prevalence of balding among men and women in Maryborough we conducted a postal survey of 5000 men and women aged 20 or older, and 427 were invited to attend for examination. Additional data was collected on dandruff, presence of gray hair. Supplementary questionnaires were sent to 340 children aged 5-9, attending a coeducational primary school. 1456 adults (34.1%) responded to the questionnaire. 396 attended for examination. The prevalence of androgenetic alopecia (AGA) increased with advancing age. 98.6% of men had bitemporal recession and severity was significantly associated with vertex and mid-frontal hair loss (p <0.01) but not age (p = 0.06). In all, 64.4% of women had bitemporal hair loss, and similar to men there was a significant association with mid-frontal hair loss (p =0.042) but not age (p =0.467). One hundred and forty children with completed questionnaires were examined. All 72 females and 68 males were assessed as stage 1 on the mid-line part and with no bitemporal recession (frequency stage 1 = 100%, 95% CI (confidence interval) 97.4%-100%). A significant but weak positive association existed between presence of gray hair and history of dandruff (p<0.01). The prevalence of mid-frontal hair loss increases with age and affects 57% of women and 73.5% of men aged 80 and over. PMID: 16382660

Br J Vener Dis. 1977 Dec;53(6):389-90.Syphilitic alopecia and Jarisch-Herxheimer reaction. Pareek SS. PMID: 606336

Sample PubMed cite¹

Alopecia syphilitica with detection of Treponema pallidum in the hair follicle. Nam-Cha SH, Guhl G, Fernández-Peña P, Fraga J. J Cutan Pathol. 2007 Dec;34 Suppl 1:37-40.

PMID: 17997737 [PubMed - indexed for MEDLINE]

Related Articles

2: Cutaneous Mycobacterium neoaurum infection causing scarring alopecia in an immunocompetent host. Martin LK, Lawrence R, Kossard S, Murrell DF. Br J Dermatol. 2007 Jul;157(1):204-6. Epub 2007 May 14. No abstract available.

PMID: 17501949 [PubMed - indexed for MEDLINE]

Related Articles

3: [Scarring tinea profunda in the pubic area due to Trichophyton verrucosum] Grunewald S, Paasch U, Gräser Y, Glander HJ, Simon JC, Nenoff P. Hautarzt. 2006 Sep;57(9):811-3. German.

PMID: 16402270 [PubMed - indexed for MEDLINE]

Dermatol Online J. 2010 Feb 15;16(2):3. Does D matter? The role of vitamin D in hair disorders and hair follicle cycling. Amor KT, Rashid RM, Mirmirani P.

Department of Dermatology, University of Texas and MD Anderson Cancer Center, Houston, Texas. rashidrashid.mdphd@yahoo.com. BACKGROUND: The role of vitamin D in the proliferation and differentiation of keratinocytes is well known within the field of dermatology. OBJECTIVE: We sought to evaluate the role that vitamin D and the vitamin D receptor play in the hair cycle and assess how this can be clinically applied to the treatment of hair disorders. METHODS: A MEDLINE search (1955-July 2009) was preformed to find relevant articles pertaining to vitamin D, the vitamin D receptor, and hair loss. RESULTS: The vitamin D receptor, independent of vitamin D, plays an important role in hair cycling, specifically anagen initiation. The role of vitamin D in hair follicle cycling is not as well understood. LIMITATIONS: The review is broad and there are limited human studies available to date. CONCLUSION: Additional studies to evaluate the role of vitamin D in the hair cycle should be done. Treatments that up regulate the vitamin D receptor may be successful in treating hair disorders and are a potential area of further study.

PMID: 20178699 http://www.ncbi.nlm.nih.gov/pubmed/20178699