The Genetically Programmed Hair Growth Cycle And Alopecia: What Is There To Know?

June 2006 in “ Expert Review of Dermatology ”

Desmond J. Tobin

TLDR The document concludes that hair loss is complex, affects many people, has limited treatments, and requires more research on its causes and psychological impact.

The 2006 document provides a comprehensive overview of hair follicle biology, the hair growth cycle, and common forms of alopecia. It explains the hair follicle as a mini organ with a cycle consisting of anagen, catagen, telogen, and exogen phases, influenced by systemic and local factors. The review emphasizes the dermal papilla's role in regulating the hair cycle, the bulge activation hypothesis for stem cell stimulation, and the complex role of androgens in hair growth. It also discusses genetic programming of hair growth patterns, racial and ethnic differences, and the influence of societal expectations. Male pattern alopecia (MPA) is identified as the most common hair loss condition, affecting a significant percentage of men by age 70, with treatments like minoxidil and finasteride available. Female pattern alopecia (FPA) is characterized by diffuse hair thinning, with limited treatment options, and the importance of considering iron status in affected women is noted. Alopecia areata (AA) is described as an immune-mediated condition with no cure, and telogen effluvium (TE) as a condition with excessive hair shedding due to various triggers. The document underscores the psychological impact of hair loss and the need for more research into genetic regulation and the aging process in alopecia.

View this study on tandfonline.com →

Discuss this study in the Community →

Research cited in this study

44 / 44 results

research Controlling the Stem Cell Niche: Right Time, Right Place, Right Strength

29 citations, December 2005 in “BioEssays”

Wnt/ß-catenin signaling is crucial for regulating skin stem cells and hair growth, with the right levels and timing needed for proper function.

research Distinguishing Androgenetic Alopecia From Chronic Telogen Effluvium When Associated in the Same Patient

63 citations, October 2005 in “Archives of Dermatology”

Shorter, thinner hairs indicate AGA, while longer, thicker hairs suggest CTE; counting and measuring shed hairs helps diagnose hair loss type.

research Modulation of Hair Growth with Small Molecule Agonists of the Hedgehog Signaling Pathway

113 citations, September 2005 in “Journal of Investigative Dermatology”

Applying a special compound can promote hair growth without harmful side effects.

research Management of Hair Loss

74 citations, April 2005 in “Dermatologic Clinics”

Minoxidil and finasteride are effective for male hair loss, minoxidil for female hair loss, and various treatments like corticosteroids work for alopecia areata; treatment should be tailored to the individual.

research Chronic Telogen Effluvium: A Study of 5 Patients Over 7 Years

54 citations, January 2005 in “Journal of The American Academy of Dermatology”

Most patients with chronic hair shedding did not progress to permanent hair loss, and one showed improvement with treatment.

research Molecular Principles of Hair Follicle Induction and Morphogenesis

479 citations, January 2005 in “BioEssays”

Hair follicle development is controlled by interactions between skin tissues and specific molecular signals.

research Limitations of Human Occipital Scalp Hair Follicle Organ Culture for Studying the Effects of Minoxidil as a Hair Growth Enhancer

30 citations, September 2004 in “Experimental Dermatology”

Scalp hair follicle culture has limits for testing minoxidil's hair growth effects.

research Burden of Hair Loss: Stress and the Underestimated Psychosocial Impact of Telogen Effluvium and Androgenetic Alopecia

162 citations, August 2004 in “Journal of Investigative Dermatology”

Hair loss causes stress and affects mental health; treatment and support needed.

research Androgenetic Alopecia in Men Aged 40-69 Years: Prevalence and Risk Factors

155 citations, December 2003 in “British Journal of Dermatology”

Hair loss increases with age; alcohol raises risk, more female partners lowers it.

research Decreased Serum Ferritin and Alopecia in Women

9 citations, November 2003 in “Journal of Investigative Dermatology”

Low serum ferritin levels are linked to hair loss in women.

research Decreased Serum Ferritin Is Associated With Alopecia in Women

163 citations, November 2003 in “Journal of Investigative Dermatology”

Low iron levels may be linked to some types of hair loss in women.

research The Presence of Trichodynia in Patients With Telogen Effluvium and Androgenetic Alopecia

46 citations, September 2003 in “International Journal of Dermatology”

Trichodynia found in 29% of TE or AGA patients, linked to psychological conditions.

research Finasteride Treatment May Not Prevent Telogen Effluvium After Minoxidil Withdrawal

14 citations, September 2003 in “Archives of Dermatology”

Finasteride may not stop severe hair loss after stopping minoxidil.

research Molecular Biology of Hair Morphogenesis: Development and Cycling

155 citations, August 2003 in “Journal Of Experimental Zoology Part B: Molecular And Developmental Evolution”

Understanding hair growth involves complex interactions between molecules and could help treat hair disorders.

research Safety of Topical Minoxidil Solution: A One-Year, Prospective, Observational Study

26 citations, July 2003 in “Journal of Cutaneous Medicine and Surgery”

Minoxidil solution safely and effectively treats hair loss.

Plasticity and Cytokinetic Dynamics of the Hair Follicle Mesenchyme During the Hair Growth Cycle: Implications for Growth Control and Hair Follicle Transformations

research Plasticity and Cytokinetic Dynamics of the Hair Follicle Mesenchyme During the Hair Growth Cycle: Implications for Growth Control and Hair Follicle Transformations

54 citations, June 2003 in “The journal of investigative dermatology. Symposium proceedings/The Journal of investigative dermatology symposium proceedings”

Disruptions in hair follicle fibroblast dynamics can cause hair growth problems.

Stress Inhibits Hair Growth in Mice by Inducing Premature Catagen Development and Harmful Perifollicular Inflammatory Events via Neuropeptide Substance P-Dependent Pathways

research Stress Inhibits Hair Growth in Mice by Inducing Premature Catagen Development and Harmful Perifollicular Inflammatory Events via Neuropeptide Substance P-Dependent Pathways

194 citations, March 2003 in “American Journal of Pathology”

Stress stops hair growth in mice by causing early hair growth phase end and harmful inflammation through a specific nerve-related pathway.

research Female Pattern Hair Loss

30 citations, October 2002 in “Journal of The American Academy of Dermatology”

Use "female pattern hair loss" term, finasteride may help, more research needed.

research Exogen, Shedding Phase of the Hair Growth Cycle: Characterization of a Mouse Model

107 citations, September 2002 in “Journal of Investigative Dermatology”

Researchers found that hair shedding happens mostly when new hair is growing and involves a unique process.

research Comparative Efficacy of Various Treatment Regimens for Androgenetic Alopecia in Men

80 citations, August 2002 in “Journal of Dermatology”

Best hair growth results from combining finasteride and minoxidil.

research Female Pattern Hair Loss

86 citations, July 2002 in “Clinical and Experimental Dermatology”

FPHL is a common, age-related, genetic hair loss with unclear causes and limited treatment options.

research Telogen Effluvium: Causes, Diagnosis, and Treatment

144 citations, July 2002 in “Clinical and Experimental Dermatology”

Telogen effluvium is a common type of hair loss that can resolve on its own or become chronic, with treatment depending on early diagnosis.

research Effects of Minoxidil 2% vs. Cyproterone Acetate Treatment on Female Androgenetic Alopecia: A Controlled, 12-Month Randomized Trial

149 citations, June 2002 in “British Journal of Dermatology”

Minoxidil works better for female hair loss, but cyproterone reduces scalp oiliness and causes menstrual issues.

The Lysosomal Protease Cathepsin L Is an Important Regulator of Keratinocyte and Melanocyte Differentiation During Hair Follicle Morphogenesis and Cycling

research The Lysosomal Protease Cathepsin L Is an Important Regulator of Keratinocyte and Melanocyte Differentiation During Hair Follicle Morphogenesis and Cycling

146 citations, May 2002 in “The American journal of pathology”

Cathepsin L is essential for normal hair growth and development.

research Molecular Mechanisms Regulating Hair Follicle Development

854 citations, February 2002 in “The journal of investigative dermatology/Journal of investigative dermatology”

Understanding hair follicle development can help treat hair loss, skin regeneration, and certain skin cancers.

research Noggin Is Required for Induction of the Hair Follicle Growth Phase in Postnatal Skin

211 citations, October 2001 in “The FASEB Journal”

Noggin is necessary to start the hair growth phase in skin after birth.

research Possible Mechanisms of Miniaturization During Androgenetic Alopecia or Pattern Hair Loss

116 citations, September 2001 in “Journal of The American Academy of Dermatology”

Hair loss occurs due to fewer papillary cells, smaller follicles, and shorter growth phases.

research The Prevalence and Types of Androgenetic Alopecia in Korean Men and Women

157 citations, July 2001 in “British Journal of Dermatology”

AGA more common in men, Koreans have lower rates and unique patterns.

research Lack of Efficacy of Finasteride in Postmenopausal Women with Androgenetic Alopecia

239 citations, November 2000 in “Journal of The American Academy of Dermatology”

Finasteride doesn't effectively treat hair loss in postmenopausal women.

research Conditional Disruption of Hedgehog Signaling Pathway Defines Its Critical Role in Hair Development and Regeneration

194 citations, May 2000 in “Journal of Investigative Dermatology”

The hedgehog signaling pathway is crucial for hair growth but not for the initial creation of hair follicles.

research The Hair Follicle: A Paradoxical Androgen Target Organ

66 citations, January 2000 in “Hormone Research in Paediatrics”

Androgens can both promote and prevent hair growth due to differences in gene expression in hair follicles.

research Differences in Hair Follicle Dermal Papilla Volume Are Due to Extracellular Matrix Volume and Cell Number: Implications for the Control of Hair Follicle Size and Androgen Responses

231 citations, December 1999 in “Journal of Investigative Dermatology”

Hair follicle size is mainly influenced by the number of cells and extracellular matrix volume, with cell number having a larger impact.

research The Biology of Hair Follicles

1113 citations, August 1999 in “The New England Journal of Medicine”

Hair follicle biology advancements may lead to better hair growth disorder treatments.

research Experimental Induction of Alopecia Areata-Like Hair Loss in C3H/HeJ Mice Using Full-Thickness Skin Grafts

131 citations, November 1998 in “The journal of investigative dermatology/Journal of investigative dermatology”

Skin grafts on mice can cause an immune response leading to hair loss, useful for studying human hair loss conditions.

research Efficacy of Topical Sensitizers in the Treatment of Alopecia Areata

132 citations, November 1998 in “Journal of the American Academy of Dermatology”

Topical sensitizers have mixed success in treating alopecia areata.

research Comparison of Alopecia Areata in Human and Nonhuman Mammalian Species

71 citations, January 1998 in “Pathobiology”

The document concludes that certain rats and mice are useful for studying hair loss in humans and testing treatments.

Different Levels of 5α-Reductase Type I and II, Aromatase, and Androgen Receptor in Hair Follicles of Women and Men with Androgenetic Alopecia

research Different Levels of 5α-Reductase Type I and II, Aromatase, and Androgen Receptor in Hair Follicles of Women and Men with Androgenetic Alopecia

416 citations, September 1997 in “Journal of Investigative Dermatology”

People with hair loss have more androgen receptors and enzymes in certain follicles, with men and women showing different patterns.

research Neural Mechanisms of Hair Growth Control

101 citations, January 1997 in “Journal of Investigative Dermatology Symposium Proceedings”

Nerves and chemicals in the body can affect hair growth and loss.

research Dermal-Epidermal Interactions in Hair Follicle Development and Maintenance

114 citations, October 1996 in “Dermatologic clinics”

Hair loss is mainly caused by hormones, autoimmune issues, and chemotherapy, and needs more research for treatments.

research The Etiology and Pathogenesis of Alopecia Areata

17 citations, July 1994 in “Journal of Dermatological Science”

The cause of alopecia areata is likely a mix of genetics, immune system issues, and environmental factors, with more research needed to understand it fully.