Methods and Techniques to Study Hair Cell Survival

6 Methods and Techniques to Study Hair Cell Survival

Jerry Shapiro and Leopoldo Duailibe Santos

Summary

Knowing how to measure all possible hair parameters is key when it comes to a hair clinic. Here, in this chapter, you will find an overview of some of the methods from the older techniques to the latest. Such methods have been classified into three subtypes: noninvasive (e.g., phototrichogram, trichoscopy), semi-invasive (e.g., trichogram), and invasive (e.g., histopathology). TrichoScan software measures many hair parameters using a videodermoscopy image; therefore, it is an example of the phototrichogram method.

Keywords: hair analysis parameters phototrichogram trichogram TrichoScan trichoscopy

Key Points

•For better understanding, the hair analysis methods have been classified into three subtypes: noninvasive, semi-invasive, and invasive.

•All hair parameters are an analysis of the four basic parameters: anagen hair, telogen hair, vellus/miniaturized hair, and terminal hair.

•Although TrichoScan is a very useful method for analyzing hair, one should be aware of its downside in order to better use it.

6.1 Introduction

There are a number of methods that one can use in order to measure all the possible parameters related to hair. The best method is the one most suitable combining what you want to measure and how much can be spent buying the equipment. One must bear in mind that any method is prone to error.

Table 6.1 lists all methods classified into noninvasive, semi-invasive, and invasive. Exploring all listed methods is beyond the scope of this text. The chapter will concentrate on the most prominent methods and will briefly mention some older techniques and some exciting new ones.

Table 6.1 Classification of available methods for hair counting and analysis classified in three different groups: noninvasive, semi-invasive, and invasive

Group	Methods
Noninvasive	•Questionnaire •Daily hair counts •Standardized wash test •60-second hair count •60-second hair count •Pull test •Global photographs •Hair weight •Cross-section trichometer/HairCheck •Contrasting felt examination •Trichoscopy/Videotrichoscopy •TrichoScan •FotoFinder/TrichoLAB •Confocal microscopy •Optical coherence tomography
Semi-invasive	•Trichogram •Unit area trichogram
Invasive	Scalp biopsy
Source: Data from Dhurat R, Saraogi P. Hair evaluation methods: merits and demerits. Int J Trichology 2009;1(2):108–119.

6.1.1 TrichoScan

TrichoScan is a computer software that is able to analyze high-quality scalp digital images, providing a report with all parameters present on Table 6.2. As an automated system, it has the advantage of not having interference from the subject nor the clinician; however, some authors have questioned its reliability.

Table 6.2 List of TrichoScan parameters

Group	Parameter
General	•Area (cm²) •Total hair count •Hair density (n/cm²)
Length	•Anagen hair (%) •Telogen hairs (%)
Width	•Density vellus hairs (n/cm²) •Density terminal hairs (n/cm²) •Ratio vellus hairs (%) •Ratio terminal hairs (%)

The procedure is performed in two steps 3 days a part. On the first day, the patient visits the doctor’s office and a specific area of the scalp is selected. A flip-card containing a 1.8cm² hole provided by the company is put onto the selected area. Using an electric razor, hairs in this 1.8cm² area are clipped (Fig. 6.1). The patient is then asked to return to the office 3 days later for the second step of the procedure.¹^,²^,³

Fig. 6.1 TrichoScan method. Figure shows a patient in whom the selected area has already been clipped and marked with red ink. This patient was part of a treatment protocol and the vertex area was chosen because of the higher number of thinning hairs compared to other area. (The image is provided courtesy of Dr. Priscila Kakizaki, São Paulo, Brazil.)

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