Trichoscopy for common hair loss diseases: algorithmic method for diagnosis

In recent years, the usefulness of trichoscopy (scalp dermoscopy) has been reported for hair loss diseases. Here, characteristic trichoscopic features of common hair loss diseases are described using a DermLite II pro or Epilight eight. Characteristic trichoscopic features of alopecia areata are black dots, tapering hairs (exclamation mark hairs), broken hairs, yellow dots and short vellus hairs. In androgenetic alopecia (AGA), hair diameter diversity (HDD), perifollicular pigmentation/peripilar sign and yellow dots are trichoscopically observed. In all cases of AGA and female AGA, HDD more than 20%, which corresponds to vellus transformation, can be seen. In cicatricial alopecia (CA), the loss of orifices, a hallmark of CA, and the associated changes including perifollicular erythema or scale and hair tufting were observed. Finally, an algorithmic method for trichoscopic diagnosing is proposed.     

Trichoscopic Findings of Hair Loss in Koreans

Background

Trichoscopic findings of hair loss have been well described for the differential diagnosis of alopecia; however, critical findings were not thoroughly investigated or compared among all ethnic groups, including Asians.

Objective

We aimed to find any characteristic trichoscopic findings in Korean alopecia patients and to verify whether those findings are closely related to previously reported observations.

Methods

Three hundred and twenty-seven patients with hair loss of various causes and 160 normal scalps were analyzed. Trichoscopic examination was performed with a polarized-light handheld dermoscope.

Results

A total of 35 patterns of trichoscopic features were represented, and certain features were significantly common or observed exclusively in a particular type of alopecia as follows: yellow dots, exclamation mark hairs, and proximal tapering hairs (alopecia areata), trichoptilosis and pointed hairs (trichotillomania), corkscrew hairs, septate hyphae hairs, and comma hairs (tinea capitis), diffuse white area, fibrotic white dots, and tufting hairs (primary cicatricial alopecia), hair diameter diversity and peripilar sign (androgenetic alopecia), and short nonvellus hairs (telogen effluvium).

Conclusion

The characteristic trichoscopic features for the differential diagnosis of alopecia in Koreans, shown as follicular, perifollicular, and hair shaft patterns, are similar to those of Caucasians; however, the frequencies of the pigment patterns are different between Koreans and Caucasians because of the contrast effect of the skin and hair color. Therefore, racial difference should be considered in the trichoscopic evaluation for differential diagnosis.     

Trichoscopy features of trichotillomania

Trichotillomania is a form of traction alopecia resulting from repetitive and compulsive hair pulling and plucking. Trichotillomania and patchy alopecia areata may have similar clinical and dermoscopic features in some cases. On trichoscopic examination, the presence of black dots, coiled or hook hair, shafts of varying lengths with fraying or split ends (trichoptilosis), and an absence of exclamation mark hairs and yellow dots are suggestive of trichotillomania.     

Coudability hairs: a revisited sign of alopecia areata assessed by trichoscopy

Background. We have previously reported several trichoscopic (dermatoscopic) characteristics, such as black dots, ‘exclamation‐mark’ hairs, broken hairs, yellow dots and clustered short vellus hairs as being useful clinical indicators for alopecia areata (AA). ‘Coudability hairs’, which are normal‐looking hairs tapered at the proximal end, have been previously reported as another sign of AA. Aims. To use trichoscopy to evaluate coudability hairs as a clinical indicator for the disease activity of AA and a substitute‐marker for the hair‐pull test. Methods. Trichoscopic examinations of hair loss and perilesional areas on the scalps of 100 East Asian patients with AA were performed using a dermatoscope. Using Spearman’s rank‐order correlation coefficient by rank test, we examined the correlations of scores between coudability and AA disease activity, severity or duration and other trichoscopic features, and then evaluated the coudability score as a surrogate‐marker for the hair‐pull test. Results. Coudability scores correlated positively with AA disease activity, hair‐pull tests, short duration, black dots and exclamation‐mark hairs, and correlated negatively with short vellus hairs. Conclusions. Coudability hairs, more closely perceived by trichoscopy, are useful‐markers for disease activity in AA and provide a surrogate‐marker for the hair‐pull test.     

'Black dots' seen under trichoscopy are not specific for alopecia areata

Background. ‘Black dots’ are macrocomedo‐like round structures localized to the follicular ostium, and are considered a specific trichoscopic feature of alopecia areata (AA). Aim. To characterize specific features of ‘black dots’, and assess their possible presence in common hair and scalp disorders. Methods. In total, 107 patients with hair loss [30 with alopecia areata (AA), 37 with androgenetic alopecia (AGA), 17 with chronic telogen effluvium (TE), 23 with other hair and scalp diseases] and 93 healthy controls were examined, using a videodermoscope with 20–70 times magnification. Results. There was a correlation between the black dots and the early acute phase of the various alopecia types with the presence of the black dots. Black dots were found in 11% (22/107) of patients with hair loss, including 53.3% (16/30) with AA; in 40% (2/5) of patients with severe chemotherapy‐induced alopecia, and in 100% of patients with dissecting cellulitis of the scalp (n = 2), hypotrichosis simplex (n = 1), and congenital aplasia cutis (n = 1). No black dots were seen in patients with AGA or TE. Conclusions. Black dots are not specific for AA, and may be present in other hair and scalp diseases.     

[Translated article] Trichoscopy in Alopecia Areata

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.     

Tricoscopia en la alopecia areata

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.     

Use of trichoscopy for the diagnosis of alopecia areata coexisting with primary scarring alopecia in a female hair loss patient

Despite patchy hair loss being typically observed in alopecia areata (AA), similar lesions can be seen in other forms of alopecia and the diagnosis is sometimes challenging. Of note, patchy primary scarring alopecia (SA) needs to be clearly distinguished from AA as SA can leave permanent hair loss. Herein, we report a previously unreported case of AA coexisting with SA successfully diagnosed by detailed trichoscopic investigation. A 42‐year‐old woman visited us with patchy hair loss lesions on the scalp. On physical examination, alopecic lesions sized up to 2 cm in diameter were observed in the right temporal and parietal regions. A gentle hair pull test collected dystrophic anagen hairs from some patches. Trichoscopy detected tapering hairs and black dots. The diagnosis of AA was made. However, some reddish patches were totally hair pull test negative, urging us to further evaluate the remaining lesions. Additional trichoscopic investigation revealed the disappearance of follicular ostia and the presence of a white and milky‐red area and peripilar scales, suggestive of SA. In histology, the clinically AA lesion showed peribulbar cell infiltration, while the potentially SA lesion demonstrated inflammatory cell infiltration around the isthmus and the decrease in hair follicles, some of which were replaced by fibrotic tissue. The final diagnosis of AA coexisting with SA was made. Intralesional corticosteroid injection improved AA but not SA. These findings emphasize the need for thorough trichoscopic examination for accurate diagnoses of rare hair loss conditions.     

Trichostasis spinulosa of the scalp mimicking Alopecia Areata black dots

Alopecia areata is a common autoimmune disorder that leads to nonscarring hair loss. Black dots, also called comedo-like cadaver hairs, can be found in almost 50% of alopecia areata patients and indicate disease activity. Trichostasis spinulosa is a follicular disorder resulting from the retention of numerous hairs surrounded by a keratinous sheath in dilated follicles. Trichostasis spinulosa is a relatively common but underdiagnosed disorder of hair follicles. Here, we describe a man with alopecia areata of the eyebrows, androgenetic alopecia and trichostasis spinulosa at the vertex and show how dermoscopy can be useful in distinguishing black dots from Trichostasis spinulosa lesions.     

Alopecia areata: Clinical presentation, diagnosis, and unusual cases

Alopecia areata (AA) is a nonscarring hair loss disorder with a 2% lifetime risk. Most patients are below 30 years old. Clinical types include patchy AA, AA reticularis, diffuse AA, AA ophiasis, AA sisiapho, and perinevoid AA. Besides scalp and body hair, the eyebrows, eyelashes, and nails can be affected. The disorder may be circumscribed, total (scalp hair loss), and universal (loss of all hairs). Atopy, autoimmune thyroid disease, and vitiligo are more commonly associated. The course of the disease is unpredictable. However, early, long‐lasting, and severe cases have a less favorable prognosis. The clinical diagnosis is made by the aspect of hairless patches with a normal skin and preserved follicular ostia. Exclamations mark hairs and a positive pull test signal activity. Dermoscopy may reveal yellow dots. White hairs may be spared; initial regrowth may also be nonpigmented. The differential diagnosis includes trichotillomania, scarring alopecia, and other nonscarring hair loss disorders such as tinea capitis and syphilis.     

斑秃皮损的皮肤镜影像及其与临床病理的关系

目的 探讨皮肤镜下斑秃皮损的微细改变及其与临床、病理相关性。方法 使用皮肤镜观察62例斑秃患者和44例其他类型脱发患者的皮损,收集患者临床及实验室资料,并对其中15例斑秃患者进行皮损部位组织病理活检,以了解皮肤镜的组织形态学基础。结果 皮肤镜下斑秃影像为黄点征、黑点征、断发、毳毛、新生短发和感叹号样毛发。黄点征发生率最高（83.9%）,而诊断斑秃的特异性指标为感叹号样毛发、黑点和断发,且后三者发生率与斑秃的活动性及轻拉发试验阳性率呈显著正相关关系。甲状腺过氧化物酶抗体升高发生率与轻拉发实验阳性率及断发发生率呈显著正相关。黄点征发生率和病理下毛囊口角栓阳性率之间呈显著正相关关系,新生短发发生率和毛囊周围肥大细胞浸润发生率以及黑点发生率则与生长期与退行期毛囊之间比例减少均呈显著负相关关系。结论 可以用黄点征作为斑秃诊断的初筛指标,而感叹号样毛发、黑点和断发对于确诊斑秃的特异性较高,且提示患者病情仍处于活动期。斑秃患者皮肤镜影像与病理有一定相关性,可用于判断病情并指导治疗。     

Trichoscopy as a useful method to differentiate tinea capitis from alopecia areata in children at Zagazig University Hospitals

Trichoscopy corresponds to the scalp, and hair dermoscopy has been increasingly used as an aid in the diagnosis, follow‐up, and prognosis of hair disorders. Trichoscopy represents a valuable link between clinical and histological diagnosis. Tinea capitis (TC) and alopecia areata (AA) are considered the most common causes of hairless patches of the scalp in pediatrics. TC may have the same clinical appearance of AA, so dermoscopy has recently become a useful diagnostic tool for AA and TC, particularly in doubtful cases. The aim of this study is to identify the trichoscopic features of TC and AA in children that may facilitate in their differentiation from each other and choosing the appropriate treatment, which is a non‐invasive method of diagnosis.     

[Translated article] Trichoscopy: An Update

Trichoscopy is a simple, noninvasive office procedure that can be performed using a handheld or digital dermatoscope. This tool has gained popularity in recent years, because it provides useful diagnostic information for hair loss and scalp disorders by enabling the visualization and identification of distinctive signs and structures. We present an updated review of the trichoscopic features described for some of the most common hair loss disorders seen in clinical practice. Dermatologists should be familiar with these helpful features, as they can significantly aid the diagnosis and follow-up of numerous conditions, such as alopecia areata, trichotillomania, and frontal fibrosing alopecia.     

Actualización en tricoscopia

Trichoscopy is a simple, noninvasive office procedure that can be performed using a handheld or digital dermatoscope. This tool has gained popularity in recent years, because it provides useful diagnostic information for hair loss and scalp disorders by enabling the visualization and identification of distinctive signs and structures. We present an updated review of the trichoscopic features described for some of the most common hair loss disorders seen in clinical practice. Dermatologists should be familiar with these helpful features, as they can significantly aid the diagnosis and follow-up of numerous conditions, such as alopecia areata, trichotillomania, and frontal fibrosing alopecia.     

Histopathologic features of alopecia areata incognito: a review of 46 cases

Background: Alopecia areata (AA) incognito represents a variant of AA characterized by acute diffuse hair thinning. Dermoscopy shows yellow dots and short regrowing hairs. The differential diagnosis with telogen effluvium (TE) and androgenetic alopecia may be difficult. Methods: In order to establish histopathological criteria for the diagnosis of AA incognito, we evaluated retrospectively 92 specimens (46 horizontal and 46 vertical) of 46 patients diagnosed with AA incognito within 1 year. All specimens were assessed for 20 features, including hair counts and follicular ratios. The numbers were compared with 46 control specimens, consisting of 21 cases of TE and 25 cases of androgenetic alopecia. Results: The following main criteria are proposed: (a) preserved number of follicular units and decreased number of terminal follicles; (b) increased number of telogen structures (mean count of 37%) with presence of at least one telogen germinal unit or/and one small telogen follicle (c) decreased terminal:vellus ratio (mean ratio of 3.3 : 1) and (d) dilated infundibular openings. Conclusion: Two histopathologic clues for AA incognito include the presence of dilated infundibular openings and small basaloid aggregates of cells with round, irregular or polygonal shape, lack of hair shaft and no apoptosis in the outer root sheath, corresponding to small telogen follicles. Miteva M, Misciali C, Fanti PA, Tosti A. Histopathologic features of alopecia areata incognito: a review of 46 cases.     

Trichoscopy: Essentials for the dermatologist

Noninvasive in vivo imaging techniques have become an important diagnostic aid for dermatology. Dermoscopy, also known as dermatoscopy, has been shown to increase the clinician's diagnostic accuracy when evaluating cutaneous neoplasms. Dermoscope, both hand-held and videodermoscope, are nowadays a basic instrument for almost all the dermatologists around the world. Trichoscopy is the term coined for dermoscopic imaging of the scalp and hair. Routinely using dermoscopy and recognizing the structures and patterns of the different types of alopecia will likely improve the observer's sensitivity for diagnosis and followup of hair and scalp disorders. Structures which may be visualized by trichoscopy include hair shafts of different types, the number of hairs in one pilosebaceous unit, hair follicle openings(dots), the peri and interfollicular areas and the vasculature. This review summarizes the current knowledge about trichoscopic findings which may aid in the diagnosis of alopecia. Besides diagnosing alopecia, it has the potential for obviating unnecessary biopsies and when a biopsy is still needed it is helpful in choosing an ideal biopsy site. Moreover, trichoscopy can be a valuable tool for evaluating the treatment response photographically at each follow-up. Finally, we have discussed the utility of dermoscopy in inflammatory scalp disorders and infections.     

Clinical significance of dermoscopy in alopecia areata: analysis of 300 cases

Objective To determine dermoscopic findings of alopecia areata (AA) from a large‐scale study that can be used as clinical indicators of disease. Methods Dermoscopic examination of areas of hair loss on the scalp of 300 Asian patients with AA was performed using a DermLite® II pro, which can block light reflection from the skin surface without immersion gels. Using the Spearman rank‐order correlation coefficient by rank test, correlations between the incidence of each dermoscopic finding and the severity of disease and disease activity were examined. The sensitivity and specificity of the findings as diagnostic clues for AA were evaluated. Results Characteristic dermoscopic findings of AA included black dots, tapering hairs, broken hairs, yellow dots, and clustered short vellus hairs (shorter than 10 mm) in the areas of hair loss. Black dots, yellow dots, and short vellus hairs correlated with the severity of disease, and black dots, tapering hairs, broken hairs, and short vellus hairs correlated with disease activity. For diagnosis, yellow dots and short vellus hairs were the most sensitive markers, and black dots, tapering hairs, and broken hairs were the most specific markers. Conclusion Dermoscopic characteristics, such as black dots, tapering hairs, broken hairs, yellow dots, and clustered short vellus hairs, are useful clinical indicators for AA.