Hair and scalp dermatoscopy

doi:10.1016/j.jaad.2012.02.013

Journal of the American Academy of Dermatology

Volume 67, Issue 5, November 2012, Pages 1040-1048

https://doi.org/10.1016/j.jaad.2012.02.013 Get rights and content

Dermatoscopy is a noninvasive diagnostic tool that allows the recognition of morphologic structures not visible by the naked eye. Trichoscopy (scalp dermatoscopy and videodermatoscopy) is useful for the diagnosis and follow-up of hair and scalp disorders. However, it is not widely used in the management of hair disorders. This review provides updated information from the literature and our experience on the dermoscopic features of the most common hair and scalp disorders. This will enable dermatologists to make fast diagnoses of tinea capitis and alopecia areata, distinguish early androgenetic alopecia from telogen effluvium, and differentiate scarring from nonscarring alopecia.

Section snippets

Dermatoscopy devices

All dermatoscopes can also be used for trichoscopy. However, optimal evaluation of scalp vascular patterns requires a magnification greater than ×20. Images can be acquired by attaching the dermatoscope (Dermlite, 3 Gen LLC, San Juan Capistrano, CA) to a digital camera, which also allows for the zooming of the images.6, 7 Special dermatoscopes that attach to the iPhone (Apple, Cupertino, CA) have been developed by FotoFinder Systems (Handyscope, Bad Birnbach, Germany) and Canfield (DermScope,

Normal scalp

There are only 3 studies on dermatoscopy of the normal scalp, all in Caucasians.10, 12, 13 In the healthy scalp there are evenly spaced groups of few hair shafts coming out of the same follicular ostium. Rakowska et al¹² reported that the temporal scalp had mostly single- and double-hair units and the occipital scalp, triple-hair units. The mean hair thickness was 0.061 ± 0.008 mm in the frontal versus 0.058 ±.007 mm in the occipital scalp.

Normal scalp vessels include interfollicular simple red

Seborrheic dermatitis and psoriasis

Dermatoscopy is very useful to distinguish scalp seborrheic dermatitis form scalp psoriasis based on the vascular pattern.10, 18

The vascular pattern of psoriasis is characterized by twisted loops (100% of the cases)¹⁰ (Fig 1). Kim et al¹⁹ recently evaluated with dermatoscopy 55 patients with scalp psoriasis and 41 patients with seborrheic dermatitis. They concluded that vascular patterns allow distinguishing the two conditions. In psoriasis they describe red dots and globules (most common in

Androgenetic alopecia

Dermatoscopy of androgenetic alopecia (AGA) is characterized by hair diameter variability greater than 20%, which is a very important distinguishing feature.²⁷ Recently, in analogy to anisocytosis in hematology, the term “anisotrichosis” has been proposed to describe diversity of hair shaft diameter observed in AGA.²⁸ Hair shaft variability can also be observed in patches of alopecia areata (AA). However, in AA dermatoscopy shows uniform miniaturization instead of hair shafts with different

Scarring alopecia

Dermatoscopy of both primary and secondary types of scarring alopecia is characterized by decreased hair density and loss of follicular openings. This is easily appreciated in nonpigmented scalp but not in the dark scalp, where both follicular openings and acrosyringeal openings appear as white dots (Fig 5). The only exception is discoid lupus erythematosus (DLE) where white dots disappear because the inflammation also affects the adnexal structures.

Congenital triangular alopecia

Dermatoscopy is a helpful tool to recognize congenital triangular alopecia in atypical locations. Dermoscopic features show absence of terminal hairs and presence of long thin vellus hair.⁵⁶

Aplasia cutis congenita

Dermatoscopy was helpful to distinguish aplasia cutis congenita from sebaceous nevus, which are the two most common differential diagnoses of congenital patchy alopecia in early infancy.⁵⁷ In sebaceous nevus, dermatoscopy showed the presence of sebaceous glands that appeared as bright yellow dots not

Conclusion

The literature and our personal experience indicate that dermatoscopy and videodermatoscopy are very useful to differentiate nonscarring from scarring alopecia, diagnose early AGA, distinguish AA from other patchy alopecia, and provide fast diagnosis of tinea capitis. Trichoscopy is a noninvasive technique that does not require expensive instruments and is very well accepted by patients. It definitely improves the quality of care of patients with alopecia and reduces the necessity of taking

References (57)

A. Tosti et al.
Dermatoscopy in the diagnosis of hair and scalp disorders
Actas Dermosifiliogr
(2009)
G. Micali et al.
Dermatoscopy: alternative uses in daily clinical practice
J Am Acad Dermatol
(2011)
A. Tosti et al.
Assessment of hair and scalp disorders
J Investig Dermatol Symp Proc
(2007)
E.K. Ross et al.
Videodermatoscopy in the evaluation of hair and scalp disorders
J Am Acad Dermatol
(2006)
R.P. Braun et al.
Dermatoscopy of pigmented skin lesions
J Am Acad Dermatol
(2005)
L.S. Abraham et al.
Pinpoint white dots in the scalp: dermoscopic and histopathologic correlation
J Am Acad Dermatol
(2010)
M. Slowinska et al.
Comma hairs: a dermatoscopic marker for tinea capitis; a rapid diagnostic method
J Am Acad Dermatol
(2008)
R. Arenas et al.
Emergence of Microsporum audouinii and Trichophyton tonsurans as causative organisms of tinea capitis in the Dominican Republic
Actas Dermosifiliogr
(2010)
R.M. Bakos et al.
Dermatoscopy for diagnosis of pediculosis capitis
J Am Acad Dermatol
(2007)
A. Di Stefani et al.
Dermatoscopy for diagnosis and treatment monitoring of pediculosis capitis
J Am Acad Dermatol
(2006)

Videodermatoscopy enhances the diagnostic capability in a case of scabies of the scalp

G Ital Dermatol Venereol

(2008)

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Traction alopecia (TA) is common, but histopathologic criteria for TA have not been objectively defined.
Determine whether the pauci-follicular unit (PFU) can be used as a diagnostic criterion for TA. Compared to a normal follicular unit (NFU), the PFU is a noninflamed follicular unit with an intact sebaceous gland but fewer than 2 follicles.
A retrospective review of 25 cases of TA and 25 cases of “normal scalp” was performed. Data included all follicles (by size and phase), sebaceous glands, and total follicular units.
Comparing data (traction vs normal), we found a significantly higher number of PFUs in cases of TA (median 6 vs 0, P < .001), which can be used as a helpful and easily recognizable diagnostic tool in diagnosing cases of TA.
Comparison to other forms of alopecia was not performed.
The number of PFUs in an alopecia biopsy can be used to establish the diagnosis of TA.
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Trichoscopy is currently regarded as an essential part of the hair loss consultation. It allows visualization of morphologic structures that are not obvious to the naked eye, including peri- and interfollicular skin surface abnormalities and changes to hair shaft thickness and shape. In this paper, we aim to discuss current knowledge on trichoscopy of the most common forms of scarring and nonscarring alopecias.
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[Translated article] Trichoscopy in Alopecia Areata
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Alopecia areata is an autoimmune disease that affects the hair follicle and can present as bald patches on the scalp and hair loss in other parts of the body. Diagnosis is clinical but can be aided by trichoscopy, a simple, rapid technique that reduces the need for invasive procedures and can also help with monitoring treatment response. We review the usefulness of trichoscopy in alopecia areata. The most common trichoscopic findings are yellow dots, black dots, exclamation mark hairs, short vellus hairs, and coudability hairs. Other, less common, findings can also help establish a diagnosis. Good response to treatment is indicated by the disappearance of black dots, broken hairs, and exclamation mark hairs. The observation of yellow dots, by contrast, indicates chronic disease and poor response to treatment.
La alopecia areata es una enfermedad autoinmune que afecta al folículo piloso. Se presenta en forma de placas alopécicas e incluso pérdida de pelo corporal. El diagnóstico es clínico. Sin embargo, la tricoscopia, una técnica valiosa no invasiva, simple y rápida, mejora el diagnóstico, la monitorización del tratamiento y reduce la necesidad de procedimientos invasivos. Realizaremos una descripción de la utilidad de la tricoscopia en la alopecia areata. Los hallazgos tricoscópicos más frecuentes de la alopecia areata son los puntos amarillos, los puntos negros, pelos en signo de exclamación, pelos vellosos cortos y pelos acodados. Sin embargo, existen otros hallazgos menos frecuentes pero útiles para realizar el diagnóstico. La buena respuesta al tratamiento implica la desaparición de los puntos negros, los pelos rotos y los pelos en signo de exclamación, pero la presencia de los puntos amarillos indica enfermedad crónica y mala respuesta.
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Androgenic alopecia (AGA) is the most common cause of hair loss worldwide, and there are a variety of pharmacotherapeutic and procedural treatment modalities available. However, before proceeding with treatment, it is important to rule out other causes of hair loss that may present similarly to AGA. A comprehensive medical history, assessment of risk factors for alopecia, careful examination, and laboratory and histopathology studies may be helpful in distinguishing between AGA and other forms of alopecia.

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: Conflicts of interest: None declared.

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ReviewHair and scalp dermatoscopy

Section snippets

Dermatoscopy devices

Normal scalp

Seborrheic dermatitis and psoriasis

Androgenetic alopecia

Scarring alopecia

Congenital triangular alopecia

Aplasia cutis congenita

Conclusion

Actas Dermosifiliogr

J Am Acad Dermatol

J Investig Dermatol Symp Proc

J Am Acad Dermatol

J Am Acad Dermatol

J Am Acad Dermatol

J Am Acad Dermatol

Actas Dermosifiliogr

J Am Acad Dermatol

J Am Acad Dermatol

J Am Acad Dermatol

J Am Acad Dermatol

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Videodermatoscopy enhances the diagnostic capability in a case of scabies of the scalp

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Review
Hair and scalp dermatoscopy