Bibbidi bobbidi bald: Two “hairowing” tales of Princess Package hairstyles

We present cases of localized alopecia on the vertex scalp of two girls after elaborate professional hairstyling marketed as the “Princess Package” at a major U.S. theme park. Localized alopecia followed pain, erythema, and delayed crusting due to necrosis of the scalp. The majority of the affected alopecic areas had evidence of regrowth at interval follow‐up, but small areas of scarring alopecia remained. We propose that these cases represent a type of alopecia caused by a combination of pressure ischemia and acute traction alopecia.     

健康人群毛发分布影响因素的研究进展

健康人群毛发分布的相关数据对于客观评价毛发生理或病理变化及评估各种治疗毛发疾病药物的疗效具有重要作用,健康人群毛发分布受到人种差异、衰老等多种因素的影响,本文将对这些因素的研究进展进行综述。     

From flint razors to lasers: a timeline of hair removal methods

Today, most do not go a day without practicing or hearing about new hair removal methods. However, little is discussed about the history of hair removal and the development of most hair removal methods since the period of cavemen. Avoiding decapitation and fitting in with society are two of many reasons for the development of this now normative practice. Knowledge of the hair growth cycle is vital in understanding the efficacy of various hair removal methods as well as the difference between epilation and depilation. While laser hair removal (LHR) is one of the most common cosmetic procedures practiced in the world, according to the FDA, the only current permanent form of hair removal is electrolysis. These two methods as well as various other ones are discussed in this article. Further developments are being made every day to better treat the removal of blonde and white hair as well as to diminish the pain of hair removal. With these developments, dermatologists will better understand the advancement of hair removal methods and the reasons why patients may seek treatment.     

African hair length in a school population: a clue to disease pathogenesis?

Background Anecdotal data suggest that combed natural African hair reaches a length steady state. Easier grooming and anticipated long hair have made relaxers popular. Objectives These hypotheses were tested in a cross‐sectional survey of 1042 school children using a piloted questionnaire and hair length measurements done on four scalp regions. Results Participants included 45% boys and 55% girls. Girls consider length important for hairstyle choice (P < 0.0001). There was no difference in mean length at 2 to 5 vs. > 5 years (P = 0.3) and at 1 to < 2 vs. 2 to 5 years (P = 0.99), suggesting that a steady state is reached within 1 year after a hair cut for combed natural hair [mean, 5.1 cm (4.3)]. Relaxed hair reached length steady state > 2 years after a haircut [mean, 10.9 cm (3.6)], was longer than natural hair (P < 0.0001), shorter than expected, and significantly shorter on the occiput than the rest of the scalp (P < 0.0001). Conclusions Persistently short combed natural hair years after a hair cut suggests that breakage eventually equals new growth (i.e., steady state), which is likely to be variable. Relaxed hair, irrespective of last haircut, is also short; chemical damage as a limit to potential lengths needs confirmation. Relatively short occipital relaxed hair could be a clue to disease pathogenesis.     

Wanted,dead and alive: Why a multidisciplinary approach is needed to unlock hair treatment potential

Human recorded history is littered with attempts to improve the perceived appearance of scalp hair. Throughout history, treatments have included both biological and chemical interventions. Hair “quality” or “perceived appearance” is regulated by multiple biological intervention opportunities: adding more hairs by flipping follicles from telogen to anagen, or delaying anagen follicles transiting into catagen; altering hair “apparent amount” by modulating shaft diameter or shape; or, in principle, altering shaft physical properties changing its synthesis. By far the most common biological intervention strategy today is to increase the number of hairs, but to date this has proven difficult and has yielded minimal benefits. Chemical intervention primarily consists of active material surface deposition to improve shaft shine, fibre‐fibre interactions and strength. Real, perceptible benefits will best be achieved by combining opportunity areas across the three primary sciences: biology, chemistry and physics. Shaft biogenesis begins with biology: proliferation in the germinative matrix, then crossing “Auber's Critical Line” and ceasing proliferation to synthesize shaft components. Biogenesis then shifts to oxidative chemistry, where previously synthesized components are organized and cross‐linked into a shaft. We herein term the crossing point from biology to chemistry as “The Orwin Threshold.” Historically, hair biology and chemistry have been conducted in different fields, with biological manipulation residing in biomedical communities and hair shaft chemistry and physics within the consumer care industry, with minimal cross‐fertilization. Detailed understanding of hair shaft biogenesis should enable identification of factors necessary for optimum hair shaft production and new intervention opportunities.     

The size and form of the medulla of human scalp hair is regulated by the hair cycle and cross-sectional size of the hair shaft

Hairs were sampled from long-haired Caucasian females, and cross-sectional measurements were performed using a rotating profile method at fixed humidity (100%). The effect of the hair cycle on medullation was investigated by examining medulla size and form along the lengths of anagen and telogen terminal hairs and also from a composite model of the entire medulla, as produced from a full cycle's growth, by amalgamating the results from the anagen and telogen hairs. The effect of hair shaft cross-sectional size on medullation has been investigated by controlling any effect of the hair cycle on terminal hairs and by use of the maximal medulla size in short, fine (vellous) hairs from the same subjects. All terminal hairs were medullated for the majority of their lengths. The presence and size of the medulla, in terminal hairs, was profoundly affected by the hair cycle. It was largest early in anagen, where the medulla minor axis, major axis and cross-sectional area represented about 26%, 23% and 7% of the corresponding whole hair shaft parameters (at 100% humidity). The medulla was virtually absent towards the end of anagen. The shape of the medulla cross-section was less elliptical than that of the whole hair shaft and was close to circular. There was no significant change in medulla shape through anagen. The form of the medulla was also affected by the hair cycle; approximately, it was continuous for the first 50% of anagen, discontinuous for the next 25% and virtually absent or absent for the final 25%. The maximal size of the medulla, as occurred in early anagen, was markedly associated with the cross-sectional size of the whole hair shaft, both within terminal hairs and between all scalp hairs. The medulla was large in terminal hairs and small or absent in very small hairs. The proportion of the whole hair shaft occupied by the medulla increased with increase in hair size and reached a maximum in terminal hairs, in which the medulla minor axis represented about 30% of the whole hair shaft minor axis. Furthermore, this proportion was constant in the terminal hairs and was not related to whole hair shaft size. Such maximal proportional medullation might represent a defining feature of terminal hairs. Variation in size of the medulla is not the cause of the previously reported cycle-dependent change in cross-sectional size of the whole hair shaft of terminal hairs.     

African hair growth parameters

BACKGROUND: Hair growth parameters have been studied mostly in caucasian hair, whereas few data on African hair have been reported in the literature. OBJECTIVES: To evaluate hair growth characteristics of African volunteers born in Africa. METHODS: Thirty-eight young adults (19 women, 19 men, mean +/- SD age 27 +/- 10 years), native of central and western Africa, took part in the study. Phototrichograms were performed in order to record three parameters of hair growth: hair density, telogen percentage and rate of growth. For each volunteer, three regions of the scalp, namely vertex, temporal and occipital areas, were assessed. RESULTS: Hair density varied from 90 to 290 hairs cm(-2), with higher counts on the vertex. No significant difference between men and women was recorded. Telogen percentage showed wide variations, from 2 to 46%, with higher levels on the temporal area and in men. The rate of growth fluctuated from 150 to 363 microm day(-1) with no difference related either to gender or to scalp region. These data were compared with those previously obtained in caucasian volunteers of comparable age, and showed significant differences between the two ethnic groups in all three parameters studied. Hair density in African volunteers was lower than that in caucasians (mean +/- SD 190 +/- 40 and 227 +/- 55 hairs cm(-2), respectively). African hair grew at a much slower rate than caucasian hair (mean +/- SD 256 +/- 44 vs. 396 +/- 55 microm day(-1)), and telogen counts were frequently higher in African hair (mean +/- SD 18 +/- 9% vs. 14 +/- 11%). CONCLUSIONS: This study demonstrated significant differences between African and caucasian hair growth parameters, which might suggest a trend towards increased hair loss in Africans, even though it contrasts with a lower and slower incidence of the development of alopecia in Africans.     

Adenosine increases anagen hair growth and thick hairs in Japanese women with female pattern hair loss: A pilot,double‐blind,randomized, placebo‐controlled trial

Adenosine upregulates the expression of vascular endothelial growth factor and fibroblast growth factor‐7 in cultured dermal papilla cells. It has been shown that, in Japanese men, adenosine improves androgenetic alopecia due to the thickening of thin hair due to hair follicle miniaturization. To investigate the efficacy and safety of adenosine treatment to improve hair loss in women, 30 Japanese women with female pattern hair loss were recruited for this double‐blind, randomized, placebo‐controlled study. Volunteers used either 0.75% adenosine lotion or a placebo lotion topically twice daily for 12 months. Efficacy was evaluated by dermatologists and by investigators and in phototrichograms. As a result, adenosine was significantly superior to the placebo according to assessments by dermatologists and investigators and by self‐assessments. Adenosine significantly increased the anagen hair growth rate and the thick hair rate. No side‐effects were encountered during the trial. Adenosine improved hair loss in Japanese women by stimulating hair growth and by thickening hair shafts. Adenosine is useful for treating female pattern hair loss in women as well as androgenetic alopecia in men.     

Histopathology of aging of the hair follicle

Hair follicles experience several changes with aging, the most noticeable of which is graying of the hair shaft due to loss of melanin. Additional changes in the diameter and length of the hair have contributed to the concept of senescent alopecia, which is different from androgenetic alopecia according to most. Graying happens in most individuals, although in different grades and starting at different ages. It is related to a decrease in the number and activity of the melanocytes of the hair bulb, which eventually completely disappear from the bulb of the white hair. Residual non‐active melanocytes remain in the outer root sheath and in the bulge, which allows for repigmentation of the hair under certain stimuli or conditions.     

Automated body hair counting and length measurement

Background/purpose: Hair loss or hair excess is a common condition. There is a growing need to quantitatively assess the success of interventions aimed at replenishing areas that lack hair or at removing hair from areas such as the back, the legs, or the arms. Non‐invasive methods that do not require staining are highly desirable because the staining process itself may affect the efficacy of the treatment. Methods: We introduce a system based on a flatbed scanner and on novel and sensitive image analysis algorithms to count the number of hairs and their individual length. Additionally, a measure of hair visibility is introduced, which allows assessing objectively the severity of the condition. Results: Our system is able to detect even hairs that are difficult to see to a human observer. It is robust to skin impurities or variations in the skin texture and colour. Scanner imaging ensures a sharp image over the whole field. The system analyses on the order of two images per minute, making it suitable for large clinical studies. Counts delivered by a human counter vs. the software were within 10% of each other (N=12). Conclusion: Based on our results, we expect that the software will be useful to a number of researchers investigating medical and cosmetic issues involving objective assessment of pilosity. The algorithm itself may be of use for other applications.     

Matting of hair: what is the role of conditioners?

Matting of the hair is a very rare and multifactorial condition affecting usually women. We present three female patients with matting of the hair as a result of the shampoo used. In all three cases, cutting of the affected hair was unavoidable.     

When is a haircut medically necessary?

We present the case of a psychotic female, admitted to our inpatient psychiatric facility, who had not cut her hair for over 20 years based on her religious beliefs. In this report, we discuss her case, evaluate whether or not it was medically necessary to cut her hair, and review several widely accepted religious practices regarding the cutting of hair.     

Loose anagen hair syndrome: an unusual cause of alopecia of cosmetic importance only

A 5-year-old girl was referred to our clinic because of a 5-month history of diffuse hair loss. Her hair was light brown and dull with evident patches of alopecia. There were no signs of scalp inflammation or scarring. A hair pull test revealed multiple hairs, easily and painlessly extracted. Light microscopic examination and trichogram were consistent with loose anagen hair syndrome. This is an unusual benign hair disorder of childhood that improves spontaneously with aging.     

Hair care practices and structural evaluation of scalp and hair shaft parameters in African American and Caucasian women

How African American hair fragility relates to hair care practices and biologic differences between races is not well understood. To assess the differences between perceptions of hair health, hair care practices, and several biologic hair parameters between Caucasian and African American women. A questionnaire on perceptions of hair health and hair care practices was administered. Biological and structural parameters of hair shaft and scalp, including growth, density, diameter, cycle, breakage, and scalp blood flow were also assessed in this case–control study. Significant differences between the Caucasian and African American women were observed in the questionnaire and biologic study data. Regarding self‐reported perceptions of hair health, there were differences in the following: hair shaft type (P < 0.001), hair breakage (P = 0.040), and desire to change hair (P = 0.001). Regarding self‐reported hair care practices, there were differences in the following: location of haircutting (P = 0.002) and washing (P = 0.010), washing frequency (P < 0.001), chemical relaxer use (P < 0.001), hooded hair dryer use (P < 0.001), and hair shaft conditioner use (P = 0.005). The two groups had similar practices in regard to the use of hair color, frequency of hair color use, chemical curling agents, and handheld blow dryer use. Regarding biological and structural parameters, there were differences in the following: hair growth rate (P < 0.001), density (P = 0.0016), diameter (P = 0.01), number of broken hairs (P < 0.001), and blood flow (P = 0.03). There was no significant difference in hair cycle parameters.The differences in hair care practices and hair fiber morphology among African American women may contribute to clinically observed variation in hair fragility and growth.