Elsevier

Dermatologic Clinics

Volume 36, Issue 4, October 2018, Pages 413-420
Dermatologic Clinics

Trichoscopy Tips

https://doi.org/10.1016/j.det.2018.05.008Get rights and content

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Key points

  • Trichoscopy is useful to diagnose early scarring alopecias and to select the optimal biopsy site in these patients.

  • Trichoscopy can easily distinguish hair loss from hair breakage and provides good information on hair shaft damage.

  • The pigmented scalp has unique trichoscopic features that make diagnosis of scarring alopecia more difficult.

  • Be aware of possible pitfalls, including scalp staining and scalp and hair shaft deposits.

How to Evaluate My Patient

First, it is important to determine in which general group of hair loss your patient best fits: diffuse, patchy, or marginal alopecia. Examination of the scalp will depend on the type of hair loss presented by the patient.4 In addition, examination of hair shafts and eyebrows may be decisive in some individuals.

Identifying basic structures in trichoscopy

A didactic way to learn the trichoscopic structures is to organize them in groups, according to their distribution on the scalp. In this regard, trichoscopic features could be divided into (1) follicular, (2) perifollicular and interfollicular; (3) vascular, and (4) hair shaft.10 The following examples are not a comprehensive review of all trichoscopic structures, but illustrative of this classification. Hair shafts are discussed in the article by Lidia Rudnicka and colleagues, “Trichoscopy in

Am I facing a scarring condition?

As a general rule, alopecias may be divided into nonscarring, a group in which patients retain the possibility of presenting hair regrowth; and scarring, when hair loss is irreversible. The trichoscopic hallmark of scarring alopecias is loss of follicular openings (Fig. 9). Therefore, when first approaching a patient with hair loss, clinicians should look for this variable to start considering possible differential diagnoses. Pitfalls do exist, as seen in patients with long-standing AA. In

My patient has a receding hairline: how trichoscopy may help?

The list of possible diagnoses of patients presenting a receding hair line includes AGA, AA in a sisaipho pattern, traction alopecia, and FFA. Differential diagnosis between them may not be trivial, particularly in early cases or in nonactive disease, in which typical clinical features may not be present. A useful clue is to check for the presence of vellus hairs in the hairline. In the normal hairline, there is a progressive “transition” from very thin vellus hairs present in the forehead to

Don’t forget the bigger picture

When clinicians and students are first introduced to trichoscopy, attempting to memorize lists of trichoscopic features for each disease is a common (but deceptive) reaction. Trichoscopy is a recent diagnostic tool and, as expected, new trichoscopic features are being continuously described. But, to understand trichoscopy, it is important to make correlation with disease pathogenesis. Many different trichoscopic features represent, in fact, the same pathogenic process. A good example of that is

Features unique to the dark scalp

Early articles discussing trichoscopy reported features mainly in the context of light-skinned patients. Only a few years ago publications started to focus on the particularities of the dark scalp, and this field still remains to be fully explored.10, 19, 28

A remarkable normal finding of the dark scalp is the visualization of a pigmented network (Fig. 10). This feature is present in the dark scalp due to the greater amount of pigment in the skin and reflects normal cutaneous architecture with

Children! What to expect in trichoscopy?

A variety of conditions are more frequently seen in children, ranging from infections and infestations to hair shaft formation disorders. The fact that trichoscopy is noninvasive and painless makes this diagnostic method particularly interesting in the evaluation of hair and scalp disorders in children.31 Even so, few studies regarding the use of trichoscopy have been done exclusively in children and much of the current knowledge derives from studies in adults. However, some features that are

Pitfalls in trichoscopy: be aware!

Pitfalls in trichoscopy are artifacts that may simulate hair disorders. It is important to identify such artifacts to avoid misdiagnosing a hair condition. The most important pitfalls are secondary to scalp deposits, scalp staining, and hair shaft deposits.

Summary

The aim of this article was to bring selected information from the literature and our clinical experience that may help dermatologists to use trichoscopy in their everyday practice. Clinicians should keep in mind that trichoscopy is a recently described and evolving technique; many new concepts are constantly arising and constant update is required.

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    Disclosure Statement: None declared.

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