key: cord-0781938-ww9i9r6y
authors: Amatya, Bibush
title: Evaluation of Dermoscopic Features in Facial Melanosis with Wood Lamp Examination
date: 2022-01-01
journal: Dermatol Pract Concept
DOI: 10.5826/dpc.1201a30
sha: a281119c6a3dfbff4d2eb475b2ccce064071d184
doc_id: 781938
cord_uid: ww9i9r6y

INTRODUCTION: Facial melanosis is one of the most common reasons for which patients refer to a dermatologist in Nepal. OBJECTIVES: The objective of this study was to evaluate the dermoscopic findings of common facial melanoses and correlate them with findings from Wood lamp examination. METHODS: This was a cross-sectional study conducted at the Department of Dermatology and Venereology, Nepal Medical College and Teaching Hospital. We recruited a total of 204 patients from July 2020 to March 2021. The most common diagnosis was melasma (37 patients) followed by melasma with steroid-induced rosacea-like dermatitis (29 patients). After collecting clinical and demographic data, patients underwent Wood lamp and dermoscopic examination. RESULTS: Dermoscopy of ashy dermatosis and nevus of Ota revealed blue-gray pigmentation forming a curvilinear pattern; café-au-lait macule and nevus spilus revealed a light brown reticular pattern with follicular sparing; and a reticular and hem-like pattern of pigmentation was observed in clofazimine-induced pigmentation, peribuccal pigmentation of Brocq and periorbital pigmentation. The degree of agreement between Wood lamp and dermoscopic findings was found to be statistically significant in melasma (κ = 0.701, P = 0.0001) and melasma with steroid-induced rosacea-like dermatitis (κ = 0.628, P = 0.0001). While the agreement between the two techniques was 100% for epidermal types, it decreased to 44.8% for dermal melasma and 61.5% for dermal melasma with steroid-induced rosacea-like dermatitis. CONCLUSIONS: Dermoscopy is useful in assessing facial melanoses. It may be supplemented with Wood lamp examination to increase diagnostic accuracy.

Facial melanoses are characterized by abnormal pigmentation of the face. These disorders include, but are not limited to, ashy dermatosis, discoid lupus erythematosus, ephelides, melasma, melasma with steroid-induced rosacea-like dermatitis, peribuccal pigmentation of Brocq, periorbital hyperpigmentation, postinflammatory hyperpigmentation, and solar lentigo. Also included are various types of nevi, such as Becker nevus, blue nevus, compound nevus, Hori nevus, intradermal nevus, junctional nevus, nevus of Ota, nevus spilus, and verrucous epidermal nevus [1] . Facial melanoses may also present as a result of ingestion of certain drugs like amiodarone, antimalarials, antipsychotics, chloramphenicol, clofazimine, pirfenidone and tetracycline [2] .

The diagnosis and differentiation of these conditions are based on history and clinical examination supplemented in some cases by Wood lamp and histopathological evaluation [3] . Dermoscopy is a noninvasive, in vivo technique that allows visualization of the subsurface structures of skin that are normally not visible to the naked eye. Wood lamp examination is another non-invasive technique that helps in the diagnosis of pigmentary disorders. It uses a specific wavelength light source to distinguish depth of pigmentation depending on different degrees of auto-fluorescence [4] . There are very few studies that have evaluated dermoscopic and Wood lamp findings for the diagnosis and classification of all facial melanoses [5] ; some studies have only focused on melasma [6] [7] [8] . We therefore aimed to evaluate the dermoscopic findings of common facial melanoses and correlate them with findings from Wood lamp examination.

This was a cross-sectional study conducted at the Department The dermoscopic findings of common facial melanoses are given in Table 2 . Acne-induced postinflammatory hyperpigmentation was characterized by reddish brown homogenous pigmentation on a reddish background ( Figure 1A A similar pattern was observed in melasma with steroid-induced rosacea-like dermatitis: epidermal (6, 20.7%), dermal (13, 44 .8%), mixed (10, 34.5%).

The degree of agreement between Wood lamp and dermoscopic findings was found to be substantial as analyzed by kappa statistics ( 

In our study, melasma was the most frequent diagnosis Few studies have compared Wood lamp and dermoscopic findings in melasma. Tamler et al [6] , in their study done in Brazil, found 44% agreement in epidermal melasma, 57%

in dermal melasma and 51% in mixed melasma. The degree of concordance was considered weak (k < 0.2). Two stud-ies done in India found a substantial degree of agreement between Wood's lamp and dermoscopic findings in melasma.

Dharni et al [7] found correlation between the two techniques in 56.25% of patients and the degree of agreement was statistically significant (k = 0.813, P = 0.0001). Manjunath et al [8] also found a good degree of correlation (k = 0.833, P = 0.0001). In our study too, the degree of agreement was significant (k = 0.701, P = 0.000). However, while the degree of agreement was 100% for epidermal type, it was only 44.8%

for dermal melasma. The discrepancies could be attributed to better visualization of arciform structures and dark brown to bluish gray irregular pigment network in dermal melasma with dermoscopy.

In our setting, melasma with steroid-induced rosacea-like dermatitis is frequently encountered [3] . The main dermoscopic features identified were light to dark brown reticular pigment network, arcuate structures, dilated tortuous branched vessels giving a polygonal appearance and terminal hairs. Jakhar et al [11] in their case report on topical steroid dependent/damaged face discovered dilated tortuous branched vessels interconnecting with each other to form a polygonal pattern on dermoscopy. In addition, white structureless areas, yellowish areas and coarse terminal hairs were also visible [11] . According to them, white structureless areas correspond to dermal atrophy. We did not encounter white structureless areas in our study indicating that this could be an incidental finding. We also found correlation between Wood lamp and dermoscopic classification of melasma with steroid-induced rosacea-like dermatitis (k = 0.628, P = 0.0001), which has not yet been reported in the literature.

Here again, while agreement was 100% in epidermal type, it decreased to 61.5% for dermal and 80% for mixed type.

Thus, while Wood lamp examination may help to differentiate epidermal melasma from other types of conditions, it may not be so accurate for dermal or mixed melasma with steroid-induced rosacea-like dermatitis.

In this study, we had one patient with ashy dermatosis and one with nevus of Ota. The dermoscopic findings in both the cases were similar; blue gray pigmentation forming a curvilinear pattern. Gray dots and globules having an irregular linear arrangement in ashy dermatosis has also been reported by Elmas et al [12] . This arrangement has been named as broken lines and semi-arcuate structures appearing as Chinese letters by Vinay et al [13] . Blue gray pigmentation forming a curvilinear pattern on dermoscopic examination of nevus of Ota has not yet been described in the literature. In the study done by Elmas et al [14] , the most common dermoscopic findings of nevus of Ota were brown and gray structureless areas having a patchy distribution. They also observed white clods in a "four dots clod" arrangement. El-Kadiri et al [15] observed blue grayish structureless areas with iridescent reflections and white rosettes in their case report on nevus of Ota. A curvilinear pattern could be discerned in the dermoscopic image in their case report, although it was not mentioned by the authors. Whether a curvilinear pattern is a characteristic feature of nevus of Ota remains to be explored.

Dark brown blotches, hem-like pattern of pigmentation on a coppery red background were observed on dermoscopic examination of patients with clofazimine-induced pigmentation. We identified only one study that had evaluated dermoscopic findings in clofazimine-induced pigmentation.

Chopra et al [16] described honeycomb pattern with yellow to white globules interspersed along a dark to skin-colored background. To best of our knowledge, this is the first study identifying hem-like pattern of pigmentation in clofazimine-induced pigmentation.

We The exaggerated skin markings imply an atopic diathesis, post-steroid abuse or constitutional type of periorbital hyperpigmentation [17] .

There were some notable limitations in the study. As it was a cross-sectional study, we could not obtain longitudinal data. This was especially true for discoid lupus erythematosus and ephelides, which have waxing and waning courses. Our hospital-based study also may be not??? representative of the general population.

Another limitation of our study is the relatively small sample size and the lack of histopathological correlation with dermoscopic examination. As this study took place during the peak of the COVID-19 epidemic in Nepal, this affected the sample size. Furthermore, most patients chose not to undergo an invasive procedure like biopsy for histopathological confirmation. We recommend future studies exploring correlation between dermoscopic and histopathological findings in all facial melanoses as dermoscopic information provided to pathologist can improve diagnostic accuracy.

The most frequent diagnoses in our study were melasma, melasma with steroid-induced rosacea-like dermatitis and various types of naevi. Dermoscopy of ashy dermatosis and nevus of Ota revealed blue gray pigmentation forming a curvilinear pattern. Café-au-lait macule and nevus spilus revealed light brown reticular pattern with follicular sparing on der-moscopy. Reticular and hem-like pattern of pigmentation was observed on dermoscopy of clofazimine-induced pigmentation, peribuccal pigmentation of Brocq and periorbital pigmentation. Although the degree of agreement between Wood lamp and dermoscopic findings were found to be statistically significant in the different types of melasma and melasma with steroid-induced rosacea-like dermatitis, the agreement was higher for epidermal types and less for dermal and mixed types. We recommend further studies exploring dermoscopic, Wood lamp and histological findings in all facial melanoses.

Clinicopathological correlation of acquired hyperpigmentary disorders

The color of skin: gray diseases of the skin, nails, and mucosa

Frequency of different types of facial melanoses referring to the Department of Dermatology and Venereology, Nepal Medical College and Teaching Hospital in 2019, and assessment of their effect on health-related quality of life

UV light set-ups for vitiligo photography, a comparative study on image quality and ease of use

Dermoscopy combined with Wood lamp, a diagnostic alternative for five pigmented lesions on the face: an observational study

Classification of melasma by dermoscopy: comparative study with Wood's lamp

Correlation of clinicodermatoscopic and Wood's lamp findings in patients having melasma

Through the eye of a dermoscope

A clinico dermoscopic study of melasma in a tertiary care center

Clinico-epidemiological Study and Quality of Life Assessment in Melasma

Dermoscopy of topical steroid damaged/ dependent face

Dermoscopic diagnosis of ashy dermatosis: A retrospective study

Dermatoscopic evaluation and histopathological correlation of acquired dermal macular hyperpigmentation

Dermoscopic Findings of Nevus of Ota

A new dermoscopic finding in Ota nevus

Correlation of dermoscopic and histopathologic patterns in leprosy: A pilot study

Clinical and dermoscopic evaluation of periorbital hyperpigmentation