ABSTRACT
The set of diagnostics tests for assessing hair and scalp disorders includes noninvasive (clinical examination, pull test, dermoscopy), semi-invasive (trichogram), and invasive (scalp biopsy) exams, among other procedures and techniques. In the last few years, many articles have highlighted the increasing importance of dermoscopy (or trichoscopy) in this field. This is a simple and easyto-perform technique that has been utilized for diagnosis and management of these patients with significant achievement, and thus it is important for dermatologists to become familiar with it. Considering the clinical examination, when first evaluating the
patient it is important to observe the scalp and the body hair distribution. In the scalp, note whether there is a diffuse, patterned, or patch alopecia. Then inspect the areas, searching for scaling, redness, and follicular openings, trying to differentiate between scarring and non-scarring alopecia. It is also important to analyze the nails, as many disorders, such as alopecia areata and lichen planopilaris, might also affect the nails. The pull test might then be performed. This test helps to deter-
mine the ongoing activity and severity of any kind of hair loss, although it is only an approximate method with many discrepancies between investigators. Each clinician should make sure their method allows a standard performance and analysis. This test is generally performed by pulling out a bundle of 50 to 60 hairs firmly grasped between the fingers; if more than 10% is pulled away, the
test is considered positive. Ideally, the patient will have notwashed the hair for 2 to 5 days before the test. Trichoscopy, which is discussed in this chapter, can be per-
formed with both handheld dermoscope (10× magnification) and videodermoscope (up to 1000× magnification), which also allows easy storage of the images. Many devices are available, and the clinician can choose according to their daily need.We recommend performing it first directly to the scalp to evaluate scaling and follicular hyperkeratosis and then with an interface solution (water or alcohol) to better analyze follicular and vascular patterns. This chapter encompasses the dermoscopic patterns in normal
white (Caucasian and Asian) and black (African-American) scalps, inflammatory and parasitic disorders, non-scarring and scarring alopecia, as well as common hair shaft disorders. Table 3.1 shows some of the typical findings. In some cases with increased hair shedding a trichogram (semi-
invasive technique) might be indicated. This test evaluates the number of plucked hairs in the different phases of the hair cycle (anagen, catagen, telogen), and the results are given as a percentage of the total number of plucked hairs. It has been classically performed by the microscope, but it is also possible to perform using the dermoscope. In some cases a scalp biopsy (invasive test) might be indicated,
especially in scarring alopecias, difficult diagnosis, scalp tumors, and in clinical studies. This is commonly performed with two 4-mm punches for horizontal and vertical sections, which will be
better evaluated by a trained dermatopathologist. It is important to choose a good site for a representative material for the diagnosis, and dermoscopy can be very useful.
