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Drug Design, Development and Therapy 2019Minoxidil was first introduced as an antihypertensive medication and the discovery of its common adverse event, hypertrichosis, led to the development of a topical... (Review)
Review
Minoxidil was first introduced as an antihypertensive medication and the discovery of its common adverse event, hypertrichosis, led to the development of a topical formulation for promoting hair growth. To date, topical minoxidil is the mainstay treatment for androgenetic alopecia and is used as an off-label treatment for other hair loss conditions. Despite its widespread application, the exact mechanism of action of minoxidil is still not fully understood. In this article, we aim to review and update current information on the pharmacology, mechanism of action, clinical efficacy, and adverse events of topical minoxidil.
Topics: Animals; Antihypertensive Agents; Hair; Humans; Hypertrichosis; Minoxidil; Molecular Structure; Sulfotransferases
PubMed: 31496654
DOI: 10.2147/DDDT.S214907 -
Current Biology : CB Feb 2009Hair is a primary characteristic of mammals, and exerts a wide range of functions including thermoregulation, physical protection, sensory activity, and social... (Review)
Review
Hair is a primary characteristic of mammals, and exerts a wide range of functions including thermoregulation, physical protection, sensory activity, and social interactions. The hair shaft consists of terminally differentiated keratinocytes that are produced by the hair follicle. Hair follicle development takes place during fetal skin development and relies on tightly regulated ectodermal-mesodermal interactions. After birth, mature and actively growing hair follicles eventually become anchored in the subcutis, and periodically regenerate by spontaneously undergoing repetitive cycles of growth (anagen), apoptosis-driven regression (catagen), and relative quiescence (telogen). Our molecular understanding of hair follicle biology relies heavily on mouse mutants with abnormalities in hair structure, growth, and/or pigmentation. These mice have allowed novel insights into important general molecular and cellular processes beyond skin and hair biology, ranging from organ induction, morphogenesis and regeneration, to pigment and stem cell biology, cell proliferation, migration and apoptosis. In this review, we present basic concepts of hair follicle biology and summarize important recent advances in the field.
Topics: Animals; Hair Diseases; Hair Follicle; Mice; Morphogenesis; Stem Cells
PubMed: 19211055
DOI: 10.1016/j.cub.2008.12.005 -
Facial Plastic Surgery Clinics of North... Nov 2018Healthy hair is vital to identity. Understanding the intricate anatomy and physiology of hair provides insight into the aging process and the eventual loss of either... (Review)
Review
Healthy hair is vital to identity. Understanding the intricate anatomy and physiology of hair provides insight into the aging process and the eventual loss of either hair pigmentation or hair shafts. Several biologics are available that have enabled altering or slowing the aging process of hair, but, unfortunately, no agent exists that can reverse the natural course. The commonly used biologics are discussed.
Topics: Alopecia; Hair; Hair Color; Hair Follicle; Humans; Skin Aging
PubMed: 30213423
DOI: 10.1016/j.fsc.2018.06.003 -
The Journal of Investigative... Dec 2007Shiny hair with a smooth texture and clean-cut ends or tapered tips is generally perceived to be healthy. Hair texture and shine relate to hair surface properties,... (Review)
Review
Shiny hair with a smooth texture and clean-cut ends or tapered tips is generally perceived to be healthy. Hair texture and shine relate to hair surface properties, whereas the integrity of hair ends relates to the hair cortex. Hair can be straight, wavy or curly, blonde, black, brown, red, gray white, and its natural variations are important to our identity. Manipulation of the normal structure of the hair shaft is epidemic and dictated by culture, fashion, and above all, celebrity. Although cosmetic procedures are intrinsically safe, there is potential for damage to the hair. Loss of lustre, frizz, split ends, and other hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair or among people with hair that is intrinsically weak. This may be due to individual or racial variation or less commonly an inherited structural abnormality in hair fiber formation. Hair health is also affected by common afflictions of the scalp as well as age-related phenomena such as graying and androgenetic alopecia. Hair products that improve the structural integrity of hair fibers and increase tensile strength are available, as are products that increase hair volume, reduce frizz, improve hair manageability, and stimulate new hair growth.
Topics: Eicosanoic Acids; Female; Hair; Hair Diseases; Hair Preparations; Humans; Hygiene
PubMed: 18004288
DOI: 10.1038/sj.jidsymp.5650046 -
Dermatologic Clinics Oct 2018Trichoscopy allows analyzing the structure and size of growing hair shafts in their natural environment in children and adults. The method replaces light microscopy,... (Review)
Review
Trichoscopy allows analyzing the structure and size of growing hair shafts in their natural environment in children and adults. The method replaces light microscopy, which requires pulling of multiple hairs for investigation. In monilethrix, trichoscopy shows uniform elliptical nodosities with intermittent constrictions. In trichorrhexis nodosa nodular thickenings along hairs shafts are visible (low magnification) or splitting into numerous small fibers along the hair shaft may be observed (high magnification). In trichorrhexis invaginata (bamboo hair) the hair shaft telescopes into itself at several points along the shaft. Trichoscopy shows small nodules along the shaft. Hairs bend and break in these diseases. Trichoscopy of pili torti shows twists of hair shafts along their long axis. In pili annulati hair shafts with alternating white and dark bands are visible. In woolly hair the examination demonstrates hair shafts with waves at very short intervals. For trichothiodystrophy polarized trichoscopy should be used. In ectodermal dysplasias, trichoscopy shows a variety of hair abnormalities, but the most characteristic finding is hair shaft pigmentation heterogeneity.
Topics: Dermoscopy; Ectodermal Dysplasia; Hair; Hair Diseases; Hair Follicle; Humans; Monilethrix; Netherton Syndrome; Trichothiodystrophy Syndromes
PubMed: 30201151
DOI: 10.1016/j.det.2018.05.009 -
Praxis Jun 1997Hair shaft disorders lead to brittle and uncombable hair. As a rule the hair feels dry and lusterless. Hair shaft abnormalities may present as localized of generalized... (Review)
Review
Hair shaft disorders lead to brittle and uncombable hair. As a rule the hair feels dry and lusterless. Hair shaft abnormalities may present as localized of generalized alterations. Genetic predisposition and exogenous factors are able to produce hair shaft abnormalities. The most important examination to analyze a hair shaft problem is light microscopy. Treatment of hair shaft disorders should focus on the cause. In addition, minimizing traumatic influences to hair shafts, such as electric dryer, permanent waves and dyes is important.
Topics: Diagnosis, Differential; Hair; Hair Diseases; Humans; Microscopy, Electron, Scanning
PubMed: 9289799
DOI: No ID Found -
International Journal of Dermatology Mar 1988
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Dermatologic Clinics Jul 1987Variations in the structure of the hair shaft are commonly seen under the microscope and are usually of little clinical significance. Defects of the hair shaft become... (Review)
Review
Variations in the structure of the hair shaft are commonly seen under the microscope and are usually of little clinical significance. Defects of the hair shaft become significant when they produce an unsightly cosmetic appearance or when they lead to the diagnosis of an underlying metabolic disorder or genetic syndrome. The article reviews hair-shaft anomalies and presents updated information and relevant clinical guidelines for diagnosing such defects.
Topics: Hair; Hair Diseases; Humans
PubMed: 3301115
DOI: No ID Found -
Dermatology (Basel, Switzerland) 2005Hair dysplasias are congenital or acquired alterations which often involve the hair shaft. Hair shaft abnormalities are characterized by changes in color, density,... (Review)
Review
Hair dysplasias are congenital or acquired alterations which often involve the hair shaft. Hair shaft abnormalities are characterized by changes in color, density, length and structure. Hair shaft alterations often result from structural changes within the hair fibers and cuticles which may lead to brittle and uncombable hair. The hair of patients with hair shaft diseases feels dry and looks lusterless. Hair shaft diseases may occur as localized or generalized disorders. Genetic predisposition or exogenous factors produce and maintain hair shaft abnormalities. Hair shaft diseases are separated into those with and those without increased hair fragility. In general, optic microscopy and polarized light microscopy of hair shafts provide important clues to the diagnosis of isolated hair shaft abnormalities or complex syndromes. To establish an exact diagnosis of dysplastic hair shafts, a structured history and physical examination of the whole patient are needed which emphasizes other skin appendages such as the nails, sweat and sebaceous glands. Profound knowledge on hair biology and embryology is necessary to understand the different symptom complexes. Therapy of hair shaft disorders should focus on the cause. In addition, minimizing traumatic influences to hair shafts, such as drying hair with an electric dryer or permanent waves and dyes, is important. A short hairstyle is more suitable for patients with hair shaft disorders.
Topics: Genetic Predisposition to Disease; Hair; Hair Diseases; Humans; Physical Examination
PubMed: 15983439
DOI: 10.1159/000085582 -
Journal of the American Academy of... Mar 2013Until a few years ago the diagnosis of hair shaft disorders was based on light microscopy or scanning electron microscopy on plucked or cut samples of hair. Dermatoscopy... (Review)
Review
Until a few years ago the diagnosis of hair shaft disorders was based on light microscopy or scanning electron microscopy on plucked or cut samples of hair. Dermatoscopy is a new fast, noninvasive, and cost-efficient technique for easy in-office diagnosis of all hair shaft abnormalities including conditions such as pili trianguli and canaliculi that are not recognizable by examining hair shafts under the light microscope. It can also be used to identify disease limited to the eyebrows or eyelashes. Dermatoscopy allows for fast examination of the entire scalp and is very helpful to identify the affected hair shafts when the disease is focal.
Topics: Dermoscopy; Eyebrows; Eyelashes; Hair; Hair Diseases; Humans
PubMed: 22940404
DOI: 10.1016/j.jaad.2012.06.041