Skin Research and Technology 2016; 22: 15–19 Printed in Singapore All rights reserved doi: 10.1111/srt.12222
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Skin Research and Technology
The trichotillometry: a technique for hair assessment A. A. El-Rifaie, A. M. Abdel Wehab, Y. Gohary and A. E. El-Rifaie Department of Dermatology, Faculty of Medicine, Beni Suef University, Beni Suef, Egypt
Background: There are many different non-invasive or invasive techniques for studying the hair state either in the normal or diseased conditions. Objective: A technique is used to evaluate the current hair status through setting a normal standard value or range of the epilating force of different hair follicle types in normal individuals. Methods: The trichotillometer is used to record in grams the force exerted to epilate a single hair in different locations of scalp. Results: Of all the plucked hairs from all the volunteers, the epilating force, the diameter, and the follicular length were calculated. The shear strain needed for epilating different hair types is calculated.
Conclusion: Using the trichotillometry technique to identify the normal range of the shear strain for different hair types is important as it may aid in diagnostic, prognostic, or even therapeutic decision making for many hair diseases.
a variety of techniques that evaluate different scalp hair parameters. These techniques have been created for quantifying many parameters in normal physiological hair states as well as assessing hair loss and monitoring response to therapy. These various methods of hair assessment are either non-invasive, semi-invasive, or invasive. The non- or semiinvasive measures include; (i) The manual collecting and counting the hairs shed daily (1) and the pull test (2), (ii) Grading scales for classification of androgenetic alopecia (3–5), (iii) High-quality photographs (6, 7), (iv) Computer high resolution image analysis (8), (v) Growth rate of scalp hair using a dye with a different color from the native hairs (9, 10), (vi) The trichogram (11) and its evolution the unit area trichogram (12), (vii) The PhotoTrichoGram involves serial magnified photographs of a target area of scalp hair (13, 14), (viii) The TrichoScan implies the PhotoTrichoGram combined with epiluminescence microscopy with digital image analysis that needs a special computer software (15). The invasive measures include; (i) Examination of follicular matrix cell kinetics as counting of the actively dividing and the number of cells entering mitosis during a given
period (16), (ii) Histopathological examination of scalp punch biopsies sectioned vertically along the length of the hair follicle and known as folliculogram (17), (iii) Measuring the volume of the hair bulb (18), and (iv) Horizontal sectioning of scalp biopsies (19). Hair is periodically shed because follicles exhibit cycles of growth (anagen), rest (telogen), and degeneration (catagen). The hair follicle lies in a tunnel-like segment of the epidermis that extends down into the dermis. The wall of the follicle has two sheaths that protect and form the growing hair shaft; the inner root sheath and the outer root sheath that forms the outer sheath of the hair. The lower part of the follicle widens out to form the hair bulb into which the dermal tissue projects to form the dermal papilla which has a network of capillary blood vessels (17). When a single hair is epilated, the force of epilation must surpass the resistance of the adhesions of the hair follicle layers causing it to succumb and the follicle will come out. This resistance is known as the shear strain or stress. The shear strain exists when two parts of a material slide across each other in any plane upon application of force parallel to that plane.
T
HERE ARE
Key words: hair – scalp – normal values – epilating force – trichotillometry
Ó 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Accepted for publication 14 February 2015
15
El-Rifaie et al.
Herein, a novel technique that can be used to evaluate the current hair status is described below. This technique aims to set a normal standard value or range of the shear strains of different hair follicle types by calculating their follicular surface area and their epilating force from different areas of the scalp in normal individuals.
Materials and Methods Six hundred and twenty-two volunteers [355 men (57.1%) and 267 women (42.9%)] aged between 14 and 59 years (mean SD; 34.7 12.9) were enrolled in this study. All the volunteers were Egyptians representing a variety of Semites and Blacks racial groups. Taking in consideration the ethical standards, all volunteers were informed about the study procedures and they accepted willingly. All the volunteers did not experience any noticeable increased hair shedding or changes in hair quality or quantity during the previous 2 years. Also, none of them had suffered from serious illness or general health disturbance during the same period. The menstruating female volunteers had no menstrual cycle irregularities, gynecological disturbance, or been taking contraceptive preparations during the previous 1 year prior to sampling. Clinically, there was no evidence of any scalp skin or hair disorder. All the volunteers followed the same standardized procedures over the 2 days prior to sampling, as detailed in the literature (12). The trichotillometer was used to pluck the hairs one by one from the scalp. It is composed of a small bulldog clamp with a minute rounded blunt 8 mm length jaw to grasp the hair firmly and securely. The handle of the clamp is welded to the axis of an intentionally modified digital scale (model DS-999, Scaletron). This digital scale is a light hand-held device with force transducer allows up to 500 g tension by 5 g graduations. The small weight of the clamp was taken into account in the calculations. Hair sampling: about 40–50 apparently normal hairs were epilated from each volunteer. Unlike the unit area trichogram (12), hairs were epilated dispersedly from scattered locations all over the scalp sparing 10–30 mm from the scalp periphery. The scalp was divided into three areas; frontal which included parietal, temporal, and occipital. The selected hairs are not supposed to represent the area hair population, they are examined singly according to their other
16
parameters. Hairs were epilated singly by holding the trichotillometer in hand and pressing on the welded bulldog handle to allow the clamp to grasp the hair just at the scalp surface. With the trichotillometer in hand, the hair is then pulled in the direction of hair growth axis to minimize damage to the hair follicle. The trichotillometer records in grams the force exerted to epilated this hair. Care should be taken not to epilate two hairs from a single cluster. Immediately after each epilation, the hair follicle is examined microscopically with a magnification of 9100, using a calibrated graticule eyepiece. The hair follicle is classified according to the growth phase into; anagen, telogen, or catagen. Dysplastic or dystrophic follicles that could not be recognized were discarded (
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Skin Research and Technology
The trichotillometry: a technique for hair assessment A. A. El-Rifaie, A. M. Abdel Wehab, Y. Gohary and A. E. El-Rifaie Department of Dermatology, Faculty of Medicine, Beni Suef University, Beni Suef, Egypt
Background: There are many different non-invasive or invasive techniques for studying the hair state either in the normal or diseased conditions. Objective: A technique is used to evaluate the current hair status through setting a normal standard value or range of the epilating force of different hair follicle types in normal individuals. Methods: The trichotillometer is used to record in grams the force exerted to epilate a single hair in different locations of scalp. Results: Of all the plucked hairs from all the volunteers, the epilating force, the diameter, and the follicular length were calculated. The shear strain needed for epilating different hair types is calculated.
Conclusion: Using the trichotillometry technique to identify the normal range of the shear strain for different hair types is important as it may aid in diagnostic, prognostic, or even therapeutic decision making for many hair diseases.
a variety of techniques that evaluate different scalp hair parameters. These techniques have been created for quantifying many parameters in normal physiological hair states as well as assessing hair loss and monitoring response to therapy. These various methods of hair assessment are either non-invasive, semi-invasive, or invasive. The non- or semiinvasive measures include; (i) The manual collecting and counting the hairs shed daily (1) and the pull test (2), (ii) Grading scales for classification of androgenetic alopecia (3–5), (iii) High-quality photographs (6, 7), (iv) Computer high resolution image analysis (8), (v) Growth rate of scalp hair using a dye with a different color from the native hairs (9, 10), (vi) The trichogram (11) and its evolution the unit area trichogram (12), (vii) The PhotoTrichoGram involves serial magnified photographs of a target area of scalp hair (13, 14), (viii) The TrichoScan implies the PhotoTrichoGram combined with epiluminescence microscopy with digital image analysis that needs a special computer software (15). The invasive measures include; (i) Examination of follicular matrix cell kinetics as counting of the actively dividing and the number of cells entering mitosis during a given
period (16), (ii) Histopathological examination of scalp punch biopsies sectioned vertically along the length of the hair follicle and known as folliculogram (17), (iii) Measuring the volume of the hair bulb (18), and (iv) Horizontal sectioning of scalp biopsies (19). Hair is periodically shed because follicles exhibit cycles of growth (anagen), rest (telogen), and degeneration (catagen). The hair follicle lies in a tunnel-like segment of the epidermis that extends down into the dermis. The wall of the follicle has two sheaths that protect and form the growing hair shaft; the inner root sheath and the outer root sheath that forms the outer sheath of the hair. The lower part of the follicle widens out to form the hair bulb into which the dermal tissue projects to form the dermal papilla which has a network of capillary blood vessels (17). When a single hair is epilated, the force of epilation must surpass the resistance of the adhesions of the hair follicle layers causing it to succumb and the follicle will come out. This resistance is known as the shear strain or stress. The shear strain exists when two parts of a material slide across each other in any plane upon application of force parallel to that plane.
T
HERE ARE
Key words: hair – scalp – normal values – epilating force – trichotillometry
Ó 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Accepted for publication 14 February 2015
15
El-Rifaie et al.
Herein, a novel technique that can be used to evaluate the current hair status is described below. This technique aims to set a normal standard value or range of the shear strains of different hair follicle types by calculating their follicular surface area and their epilating force from different areas of the scalp in normal individuals.
Materials and Methods Six hundred and twenty-two volunteers [355 men (57.1%) and 267 women (42.9%)] aged between 14 and 59 years (mean SD; 34.7 12.9) were enrolled in this study. All the volunteers were Egyptians representing a variety of Semites and Blacks racial groups. Taking in consideration the ethical standards, all volunteers were informed about the study procedures and they accepted willingly. All the volunteers did not experience any noticeable increased hair shedding or changes in hair quality or quantity during the previous 2 years. Also, none of them had suffered from serious illness or general health disturbance during the same period. The menstruating female volunteers had no menstrual cycle irregularities, gynecological disturbance, or been taking contraceptive preparations during the previous 1 year prior to sampling. Clinically, there was no evidence of any scalp skin or hair disorder. All the volunteers followed the same standardized procedures over the 2 days prior to sampling, as detailed in the literature (12). The trichotillometer was used to pluck the hairs one by one from the scalp. It is composed of a small bulldog clamp with a minute rounded blunt 8 mm length jaw to grasp the hair firmly and securely. The handle of the clamp is welded to the axis of an intentionally modified digital scale (model DS-999, Scaletron). This digital scale is a light hand-held device with force transducer allows up to 500 g tension by 5 g graduations. The small weight of the clamp was taken into account in the calculations. Hair sampling: about 40–50 apparently normal hairs were epilated from each volunteer. Unlike the unit area trichogram (12), hairs were epilated dispersedly from scattered locations all over the scalp sparing 10–30 mm from the scalp periphery. The scalp was divided into three areas; frontal which included parietal, temporal, and occipital. The selected hairs are not supposed to represent the area hair population, they are examined singly according to their other
16
parameters. Hairs were epilated singly by holding the trichotillometer in hand and pressing on the welded bulldog handle to allow the clamp to grasp the hair just at the scalp surface. With the trichotillometer in hand, the hair is then pulled in the direction of hair growth axis to minimize damage to the hair follicle. The trichotillometer records in grams the force exerted to epilated this hair. Care should be taken not to epilate two hairs from a single cluster. Immediately after each epilation, the hair follicle is examined microscopically with a magnification of 9100, using a calibrated graticule eyepiece. The hair follicle is classified according to the growth phase into; anagen, telogen, or catagen. Dysplastic or dystrophic follicles that could not be recognized were discarded (
