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Dermoscopy, also known as dermatoscopy, epiluminescence microscopy, or skin surface microscopy is a non-invasive, in-vivo technique that has traditionally been useful for the evaluation of suspicious skin lesions. It can help identify lesions and differentiate melanocytic lesions from dysplastic lesions, melanomas, or non-melanoma skin cancers such as basal cell carcinoma or squamous cell carcinoma. Furthermore, over the past several years, the use of dermoscopy has expanded to include utilization for diagnosis of dermatological disorders including inflammatory dermatosis, pigmentary dermatosis, infectious dermatosis, and disorders of the hair, scalp, and nails. As the utility of dermoscopy continues to expand, practitioners in almost all specialties should be familiar with this simple, non-invasive and high-yield diagnostic technique. This activity reviews the various uses for dermoscopy across multiple specialties and stresses the role of team-based interprofessional care. Objectives: Explain the principles of dermoscopy in cutaneous diagnosis. Review the expanding applications of dermoscopy beyond the diagnostic realm. Describe common errors associated with interpretation of dermoscopy. Summarize interprofessional team strategies to improve awareness of dermoscopy as a tool that can be used by almost any specialty to assist with the diagnosis of a diverse array of conditions. Access free multiple choice questions on this topic.

Cutaneous diagnosis is often, but not always, visually based. Dermatologists tend to encounter situations where the possibility of multiple differentials complicates the diagnosis and mandates investigations for confirmation. Methods commonly employed for cutaneous diagnosis may be invasive (skin and scalp biopsy), semi-invasive (slit skin smears, trichogram, etc.) or non-invasive (e.g., KOH smear, nail clipping, hair count for hair loss).[1] Dermoscopy, also known as epiluminescence microscopy, or skin surface microscopy, is a non-invasive, in-vivo technique, which has traditionally found use in the evaluation and differentiation of suspicious melanocytic lesions from dysplastic lesions and melanomas, as well as keratinocyte skin cancers such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).[2] Over the last several years, the use of dermoscopy has been increasing in the context of general dermatological disorders including inflammatory dermatosis, pigmentary dermatosis, infectious dermatosis, and disorders of the hair, scalp, and nails. Some terms are used to describe specific indications: pigmentaroscopy for pigmented lesions, trichoscopy of the scalp and hair, onychoscopy of the nails, inflammoscopy for inflammatory dermatosis and lesions, as well as entomodermoscopy of skin infestations and infections [3][4]. The role of dermoscopy in diagnosing disorders of general dermatology has undergone elaborate discussion [4]. In this chapter, we shall review the plethora of extra-diagnostic indications of this technique and highlight technical aspects worth considering.

As a non-invasive technique, dermoscopy is essentially free of complications. The only issue is the minimal possibility of cross-infection between patients, especially with contact dermoscopy. Many tricks can obviate the possibility of cross-infection: 1) Use of polarized non-contact dermoscopy. 2) Disinfection of the lens (in case of contact dermoscopy) or the rim of the USB video-dermatoscope with isopropyl alcohol after examining each patient. 3) Use of disposable transparent lens shielding material like a cling film or soft plastic caps over the device; the latter are now being provided complimentary with most of the high-quality dermatoscopes - for use in both hand-held and USB video-dermatoscopes. Minor issues worth consideration 1) One should be aware of artifacts of dermoscopy that may suffer from incorrect interpretation.[6] Common artifacts include vermillion powder, colored powders, dust particles, hair dye, henna, hair fibers minoxidil crystals, hair styling gel, etc. in trichoscopy, dust particles, topical applications especially sunscreen and make-up ingredients during dermoscopy of the face, and nail paint and varnish in onychoscopy. The area to be scoped should be thoroughly cleaned with alcohol first to remove these artifacts. 2) Inter-device color difference in images: Different dermatoscopes tend to give images with a mildly skewed color balance. One must be aware of that and interpret results accordingly 3) Differences in different Fitzpatrick skin types: It is now amply clear that many features that are easy to appreciate in Fitzpatrick types I-II skin, are either not seen or are obscured in darker skin types. Honeycombing in the scalp is considered suggestive of androgenetic alopecia (AGA) in Fitzpatrick skin phototypes I to III but is a normal finding in the scalp of individuals with darker skin types. The colors (black, brown, gray, and blue) that have their basis in the histological level are neither easy to observe nor interpret in dark skin. Brown pigmented structures are often seen on dermoscopy of various disorders in ethnic skin due to the propensity of post-inflammatory hyperpigmentation, and thus warrant careful interpretation.

3) Differences in different Fitzpatrick skin types: It is now amply clear that many features that are easy to appreciate in Fitzpatrick types I-II skin, are either not seen or are obscured in darker skin types. Honeycombing in the scalp is considered suggestive of androgenetic alopecia (AGA) in Fitzpatrick skin phototypes I to III but is a normal finding in the scalp of individuals with darker skin types. The colors (black, brown, gray, and blue) that have their basis in the histological level are neither easy to observe nor interpret in dark skin. Brown pigmented structures are often seen on dermoscopy of various disorders in ethnic skin due to the propensity of post-inflammatory hyperpigmentation, and thus warrant careful interpretation. 4) Lack of 'dermoscopic nomograms': To master the interpretation of histopathology, one must be thoroughly conversant with the normal histology, taking into account expected physiological variations due to a particular part of the human body, age, and gender. For example, the normal mucoscopic images from buccal mucosa reveal plentiful vessels, which should not be confused as a pathological feature. There is an urgent need to have an image bank of such site-specific, and skin type-specific dermoscopic nomograms to minimize errors in the interpretation of dermoscopic structures.

Although dermoscopy is an excellent tool for triage, it needs to be combined with the macro clinical picture and histopathology to be conclusive. The role of the dermatopathologist is vital in this regard. From what used to a clinicopathological correlation, we are moving towards a clinical-dermoscopic-pathological correlation. As far as levels of evidence are concerned, a recently published Cochrane meta-analysis sums it up aptly-although evidence-based is limited, the conclusion is that when specialists use dermoscopy, it is a better tool for the diagnosis of melanoma as compared to simple visual examination. Also, dermoscopy is more effective when interpreted with the actual patient, rather than with a dermoscopy image.[36] Dermoscopy should not be considered as an 'ancillary' or 'optional' tool now, at least for a dermatologist. Dermoscopy is not only for dermatologists, rather the skill should be acquired and customized by other specialists too, especially general practitioners/family physicians, pediatricians, and dermatosurgeons. Pediatricians in particular must get acquainted with dermoscopy as the non-invasive and visually engaging property of dermoscopy and its images make pediatricians' interaction with an anxious child much more convenient.[7] The use of dermoscopy by general physicians is very low. The impact of subspecialization and dermatoscopy use on the accuracy of melanoma diagnosis among primary care doctors in Australia.[37] With respect to general/family physicians, regrettably, many barriers have resulted in extremely low usage of dermoscopy. Some of these barriers include - costs of dermoscopy—both the equipment cost and the relatively inadequate reimbursement for its use in practice, the need for dermoscopy training, lack of information about learning resources and the unwillingness to invest time, both for training and to use dermoscopy in practice.