Hair shaft videodermoscopy in netherton syndrome

Trichoscopy beyond scalp. A narrative review

Dermoscopy is becoming an indispensable tool in everyday practice, with an expanding range of applications. Trichoscopy is effective not only in establishing the diagnosis of scalp disorders but also in the follow-up of treatment. The MEDLINE database was searched using the terms "dermoscopy" and "trichoscopy" in combination with each of the following: "axilla," "pubic area," "beard," "eyebrows," "eyelashes," and "body hairs." We included case reports, case series, and review articles mentioning the previous terms. By providing an updated review from the literature, we aimed to emphasize the potential uses of trichoscopy in detecting diseases in hairy locations other than the scalp. Various inflammatory conditions, infections, and infestations are discussed.

Hair abnormality in Netherton syndrome observed under polarized light microscopy

BACKGROUND

Trichorrhexis invaginata, the main diagnostic feature of Netherton syndrome, is often difficult to detect, especially in adult patients.

OBJECTIVE

We sought to describe a characteristic feature of hairs in Netherton syndrome using a polarized light microscope and the underlying histopathologic changes.

METHODS

Hairs obtained from 8 patients with Netherton syndrome were observed under polarized light, and we evaluated the correlation between number of band-like patterns and disease severity.

RESULTS

Under polarized microscopy, the hair shafts of 8 patients showed a characteristic band-like pattern under polarized light that was not observed in healthy control individuals or patients with atopic dermatitis. This discontinuity of polarized light shows a band-like pattern in which the bands mostly ranged from 0.1 to 1.0 mm in width. The observed ratio of this finding was significantly higher than that of trichorrhexis invaginata observed under light microscopy, and patients with severe dermatitis tended to have a higher ratio than those with less severe dermatitis.

LIMITATIONS

Comparative examination among other congenital ichthyoses was not performed.

CONCLUSIONS

A band-like pattern in hairs with polarized light microscopy can be seen in Netherton syndrome and may have potential utility as a diagnostic marker.

Trichoscopy as a diagnostic tool in trichorrhexis invaginata and Netherton syndrome

Netherton syndrome is a rare autosomal recessive disease characterized by erythroderma, ichthyosis linearis circumflexa, atopy, failure to thrive and a specific hair shaft abnormality called trichorrhexis invaginata or bamboo hair, considered pathognomonic. We report the case of a 4-year-old boy with erythroderma since birth, growth deficit and chronic diarrhea. Trichoscopy was used to visualize typical bamboo and "golf tee" hair and of key importance to diagnose Netherton syndrome. We suggest the use of this procedure in all children diagnosed with erythroderma.

Trichoscopy findings in loose anagen hair syndrome: rectangular granular structures and solitary yellow dots

BACKGROUND

Loose anagen hair syndrome (LAHS) is typically diagnosed in girls older than 2 years who present with hair that "will not grow". Hair microscopic examination shows absent inner and outer root sheaths, ruffling of the cuticle on the proximal hair shaft and deformed pigmented anagen bulbs.

OBJECTIVE

The aim of the study was to assess whether there are characteristic trichoscopic features favoring the diagnosis of LAHS.

PATIENTS AND METHODS

Eighty nine children patients were included into the study (24 girls with LAHS, 25 with alopecia areata, 20 with telogen effluvium and 20 healthy children). In all groups trichoscopy was performed. Trichoscopy images were analyzed for abnormalities in the hairs shafts, the hair follicle openings and the interfollicular area.

RESULTS

Dirty dots were present in all groups. A unique feature of LAHS was the presence of rectangular black granular structures which differs from dense black dots seen in patients with alopecia areata. This feature was observed in 71% of patients with LAHS. Follicular units with single hairs constituted 92,9% of hair units in these patients (65,5% in telogen effluvium and 53% in the control group). Solitary yellow dots were found in 50% of patient with LAHS and in 24% of patients with alopecia areata, but was not found in control group or in patients with telogen effluvium.

CONCLUSION

The trichoscopy features favoring the diagnosis of LAHS are: rectangular black granular structures, solitary yellow dots and major predominance of follicular units with single hairs.

Evaluation and diagnosis of the hair loss patient: part II. Trichoscopic and laboratory evaluations

The use of trichoscopy for evaluating a number of hair and scalp disorders is gaining popularity. It is a simple and noninvasive in vivo tool for visualizing hair shafts and the scalp. Recently, alopecias have been classified according to their trichoscopic findings. The second part of this 2-part continuing medical education article reviews recent advances in this field and describes a systematic approach for using the differential diagnostic findings of trichoscopy in alopecia.

Rapid and easy diagnosis of Netherton syndrome with dermoscopy

BACKGROUND

Netherton syndrome is a rare autosomal recessive disease demonstrating ichthyosis linearis circumflexa, atopic findings, and hair shaft anomalies. Trichorrhexis invaginata is the pathognomonic hair shaft anomaly seen in this syndrome.

OBJECTIVE

In recent years, hair shaft anomalies have been described as "matchstick" and "golf tee" signs. We present a patient with Netherton syndrome diagnosed by the presence of matchstick and golf tee hairs in addition to trichorrhexis invaginata.

Is trichoscopy a reliable tool to diagnose early female pattern hair loss?

Background:

Female pattern hair loss (FPHL) presents with visible patterns of hair loss, thus making a bedside diagnosis possible. However, there are cases of FPHL presenting without any visible hair thinning, making it necessary to subject them to a scalp biopsy to make a diagnosis.

Aim:

The aim of the following study is to determine if trichoscopy can be used as a bedside tool to diagnose Early FPHL in women presenting without any visible thinning of hair, using >20% hair diameter diversity – anisotrichosis, as the diagnostic criteria.

Materials and Methods:

Trichoscopy was performed on 20 cases of early FPHL (biopsy proven), 63 normal controls and 29 Grade 2 FPHL Controls.

Results and Discussion:

In the biopsy proven FPHL cases, 75% showed anisotrichosis on trichoscopy. This finding was significantly higher in FPHL Cases compared to normal controls. As expected, 93% of Grade 2 FPHL controls also showed the same finding. Trichoscopy was found to be 75% sensitive and 61.54% specific in diagnosing early FPHL. Thus, a negative result would be more indicative of absence of disease, however, a positive result would not always indicate the presence of disease.

Role of trichoscopy in children's scalp and hair disorders

Hair and scalp disorders in children may originate from the hair itself, scalp skin, or infectious causes and be congenital or acquired. The most common sign is alopecia, frequently brought on by tinea capitis, patchy alopecia areata, or trichotillomania. Sometimes less frequent and clinically more elusive conditions such as initial androgenetic alopecia, congenital triangular alopecia, or alopecia areata incognita may be responsible for hair loss. The noninvasive technique known as trichoscopy is being used more frequently, aiding in the prompt differential diagnosis and follow-up of many of these diseases, oftentimes providing further examination before a treatment decision is made. This review of trichoscopy of the main scalp and hair disorders afflicting children and adolescents discusses the most important dermoscopic criteria and the usefulness of this technique.

Trichoscopy: how it may help the clinician

Trichoscopy (or dermoscopy of hair and scalp) is an easy in-office technique that may be performed with a handheld dermoscope or a digital videodermoscopy system. This method is gaining increasing popularity, because it may be applied in differential diagnosis of multiple hair and scalp diseases. The focus of this article is application of trichoscopy in differential diagnosis of the most frequent hair and scalp diseases in dermatologic practice. Trichoscopy of genetic hair shaft abnormalities are briefly addressed. A new classification of perifollicular and interfollicular skin surface abnormalities is proposed.

Trichoscopy update 2011

Trichoscopy performed with a handheld dermoscope or a videodermoscope became an indispensable tool in differential diagnosis of hair and scalp diseases. Current research is focusing on trichoscopy of: 1) non-cicatricial alopecia, 2) cicatricial alopecia, 3) hair shaft disorders, and 4) inflammatory scalp diseases. This review summarizes current knowledge in these four fields of research. In all non-cicatricial alopecias presence of empty follicular openings is a common trichoscopy finding. In alopecia areata black dots and micro-exclamation mark hairs and tapered hairs correlate with disease activity, whereas yellow dots and vellus hairs correlate with disease severity. In androgenic alopecia trichoscopy shows hair shaft thickness heterogeneity, multiple thin and vellus hairs, yellow dots, perifollicular discoloration, and predominance of follicular units with only one hair. These features predominate in the frontal area. In all forms of cicatricial alopecia, trichoscopy shows milky-red or ivory-white areas lacking follicular openings. In classic lichen planopilaris trichoscopy shows perifollicular inflammation, tubular perifollicular scaling, elongated, concentric blood vessels and "classic white dots", which merge to form white areas. Frontal fibrosing alopecia shows mild perifollicular scaling. Folliculitis decalvans is characterized by tufted hairs, large follicular pustules with emerging hair shafts and perifollicular starburst pattern hyperplasia. In dissecting cellulitis characteristic findings are "3D" yellow dots imposed over dystrophic hairs, large, yellow amorphous areas and pinpoint white dots with a whitish halo. Trichoscopy is particularly useful to diagnose hair shaft abnormalities in trichorrhexis nodosa, trichorrhexis invaginata, monilethrix, pili torti, and pili annulati. The method may be also useful in diagnosing inflammatory scalp diseases. In discoid lupus erythematosus trichoscopy shows large arborizing vessels and large hyperkeratotic folliculilar yellow dots. Trichoscopy of scalp psoriasis shows regularly distributed twisted and lacelike blood vessels, whereas in seborroic dermatitis thin arborizing vessels may be observed. In tinea capitis trichoscopy shows comma, corkscrew and zigzag hairs. Examination tinea capitis may be facilitated by UV-light enhanced trichoscopy (UVET). In conclusion, trichoscopy is a non-invasive method which may be applied in differential diagnosis of most hair and scalp diseases.

Trichoscopy in genetic hair shaft abnormalities

BACKGROUND

Diagnosis of hair shaft abnormalities is based on light microscopic examination of more than 50 plucked hairs. The aim of this study was to verify whether hair shaft abnormalities may be visualized by trichoscopy (hair and scalp videodermoscopy) and to analyze trichoscopic features of common genetic hair shaft dysplasias.

METHOD

Patients with known genetic hair shaft disorders were included into the study. Trichoscopy was performed with the use of Fotofinder II videodermoscope. Images performed at 20-fold and 70-fold magnification were analysed. In selected cases 160-fold magnification was used for better visualization of hair shafts.

RESULTS

Our results show that characteristic light microscopy features of Netherton syndrome, monilethrix, woolly hair syndrome, pili torti, pili annulati and trichothiodystrophy may be visualized by trichoscopy.

CONCLUSION

Genetic hair shaft abnormalities may be diagnosed by trichoscopy in a single diagnostic session without the need of plucking or cutting them for diagnostic purposes.