International Journal of Trichology International Journal of Trichology
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 Table of Contents  
Year : 2020  |  Volume : 12  |  Issue : 4  |  Page : 195-196  

Dodging Pitfalls in Trichoscopy: How to Nail the Right Diagnosis

1 Department of Dermatology, Federal of Bonsucesso Hospital, Brazil
2 Department of Dermatology, State University of Rio de Janeiro, Brazil
3 Department of Dermatology, Federal State University of Rio de Janeiro, Rio de Janeiro, Brazil
4 Department of Dermatology, Santa Casa de Misericórdia of Recife Hospital, Pernambuco, Brazil
5 Department of Dermatology, State University of Pará, Pará, Brazil

Date of Submission19-Jun-2020
Date of Decision20-Jul-2020
Date of Acceptance23-Jul-2020
Date of Web Publication19-Sep-2020

Correspondence Address:
Dr. Caren dos Santos Lima
Municipalidade Street, 985/1903, Umarizal, Belém
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijt.ijt_9_20

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How to cite this article:
Barreto Td, Melo DF, Alves Td, Lima MM, Lima CS. Dodging Pitfalls in Trichoscopy: How to Nail the Right Diagnosis. Int J Trichol 2020;12:195-6

How to cite this URL:
Barreto Td, Melo DF, Alves Td, Lima MM, Lima CS. Dodging Pitfalls in Trichoscopy: How to Nail the Right Diagnosis. Int J Trichol [serial online] 2020 [cited 2022 Dec 6];12:195-6. Available from: https://www.ijtrichology.com/text.asp?2020/12/4/195/295490


Trichoscopy refers to dermoscopy of the scalp and hairy areas, and several patterns have already been associated with alopecias.[1] Trichoscopic findings not related to diseases have been reported. The said findings could be potentially mistaken with typical signs of alopecias, which in turn might lead to misdiagnosis and delayed treatment.[2] This article's goal is to provide practical tips on how to dodge these pitfalls and illustrate them. Artifact images are compared to clinically relevant ones to clarify their peculiarities.

Dirty dots, leftover hair dyes, and cosmetic fibers can hinder correct trichoscopic interpretation and mimic clinically relevant findings.[2]

Dirty dots are a normal trichoscopic finding in healthy children and the elderly, resulting from the scalp's inability to repel environmental debris due to a decrease in sebaceous gland activity.[3] Clinically, they appear as particles of multiple colors, irregularly distributed. Black dots represent pigmented hair shafts broken at follicular ostia level, described in several diseases.[1],[3] In alopecia areata (AA), these structures are typically related to disease activity.[1] Unlike black dots, dirty dots are not necessarily located in follicular openings and are easily removed after shampooing[2] [Figure 1]a and [Figure 1]b.
Figure 1: (a) Dirty dots: Environmental residues that are physiologically found in children and the elderly. (b) Black dots: Result from hair shafts broken at follicular ostia level. Unlike black dots, dirty dots are not necessarily associated with follicular openings

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Broken hairs result from transverse fracture of terminal shafts. They can be found in several alopecias and in AA are related to disease activity.[1] Trimmed shafts from patients with short hair recently cut can resemble broken hairs. These fragments have different lengths, are irregularly distributed, and are not attached to the scalp, which helps in distinction[2] [Figure 2]a and [Figure 2]b.
Figure 2: (a) Haircut: Trimmed shafts from patients with short hair recently cut can resemble broken hairs. (b) Broken hairs: They result from transversal break of terminal hairs and are correlated with activity of some diseases

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Another pitfall may arise when patients use hair dyes. Permanent hair dye accumulation is usually restricted to follicular ostia, appearing as small dots. Semi-permanent hair dye deposits are more spread on the scalp, seen as coarser dots. Depending on the shade used, hair dye may simulate black, red, or yellow dots.[4] Yellow dots correspond to dilated follicular infundibulum filled with keratotic material and sebum, typically found in AA, discoid lupus erythematosus (DLE), androgenetic alopecia (AGA), and dissecting cellulitis.[1] Red dots can be a feature of DLE or be found on normal scalp, related to rich vasculature surrounding hair follicles.[5] To avoid these pitfalls, it is important to inquire about hair dye use and instruct patients to wash the scalp at least twice before examination, thus minimizing residues accumulation[4] [Figure 3]a, [Figure 3]b and [Figure 4]a, [Figure 4]b.
Figure 3: (a) Permanent hair dye: Its accumulation is usually restricted to follicular ostia, having the appearance of small dots. (b) Yellow dots: Correspond to dilated follicular infundibulum filled with sebum and keratin

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Figure 4: (a) Semi-permanent hair dye: They deposit dispersedly on scalp, coloring inter and perifollicular areas, generating coarser dots. (b) Red dots: Represent rich vascularization of hair follicles. They can be physiological finding or seen in diseases such as lupus

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Cosmetic keratin fibers are inert camouflage, which attach electrostatically to hair shafts and may be misinterpreted as miniaturized or short regrowing hairs.[2] Short regrowing hairs can be found in AA, associated with disease remission.[1] They were also described in trichotillomania, traction alopecia, and telogen effluvium. Hair miniaturization is a typical trichoscopic finding of AGA.[1] Washing the scalp before examination removes cosmetic fibers and helps to avoid this artifact [Figure 5]a and [Figure 5]b.
Figure 5: (a) Hair fibers: Cosmetic camouflage made of keratin that attaches electrostatically to hair shafts. (b) Short regrowing hairs: They have normal pigmentation and an upright position with a sharp distal end

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Artifacts in trichoscopy are more common than imagined and represent possible pitfalls that may lead to incorrect diagnoses. This article addresses four of these findings, comparing them with clinically relevant trichoscopic signs. Dermatologists must be aware of these artifacts to recognize them and minimize misinterpretations. Thorough anamnesis and correct orientations to patients are the keys to avoid trichoscopic pitfalls.

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Conflicts of interest

There are no conflicts of interest.

   References Top

Lacarrubba F, Micali G, Tosti A. Scalp dermoscopy or trichoscopy. Curr Probl Dermatol 2015;47:21-32.  Back to cited text no. 1
Rudnicka L, Rakowska A. Tips, tricks, and artifacts in trichoscopy. In: Rudnicka L, Olszewska, M, Rakowska, A. Atlas of Trichoscopy. 1st Ed. London: Springer 2012. p 121 41.  Back to cited text no. 2
Miteva M, Lima M, Tosti A. Dirty Dots as a Normal Trichoscopic Finding in the Elderly Scalp. JAMA Dermatol 2016;152:474-6.  Back to cited text no. 3
Angra K, LaSenna CE, Nichols AJ, Tosti A. Hair dye: A trichoscopy pitfall. J Am Acad Dermatol 2015;72:e101-2.  Back to cited text no. 4
Pirmez R, Piñeiro-Maceira J, Almeida BC, Sodré CT. Follicular red dots: A normal trichoscopy feature in patients with pigmentary disorders? An Bras Dermatol 2013;88:459-61.  Back to cited text no. 5


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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