Dermatology: Practical and Conceptual Review | Dermatol Pract Concept 2019;9(3):1 169 Dermatology Practical & Conceptual Introduction Dermoscopy is a fascinating bridge between clinical and histological examination that has become a key tool for the evaluation of pigmented and nonpigmented skin tumors because of its ability to reveal findings not visible to the naked eye [1,2]. Besides this classic application, it is gaining appreciation in areas other than dermato-oncology, especially inflammatory dermatology (inflammoscopy) [1,2]. While a well-established and structured approach for the analysis of dermoscopic images is available in the field of tumoral diseases, criteria and terminology used for inflam- matory dermatoses in the literature are often variable, meta- phoric, and poorly comprehensible, with consequent lack of a systematic analytic approach [1,2]. For this reason, a set of 5 dermoscopic parameters (with a total of 31 subitems) has been proposed by a consensus document of the Interna- tional Dermoscopy Society as a basic guide to use in general dermatology [3]: (I) vessels (including morphology and dis- tribution); (II) scales (including color and distribution); (III) follicular findings; (IV) “other structures” (structures other than vessels/scales; including color and morphology); and (V) “specific clues” (features that, when present, are strongly suggestive of only 1 diagnosis due to a strict dermoscopic- pathological correlation). As vascular structures and scales are the main characteriz- ing dermoscopic features of inflammatory diseases, the selec- tion of proper equipment is of utmost importance [1]. In this Dermoscopy of Inflammatory Dermatoses (Inflammoscopy): An Up-to-Date Overview Enzo Errichetti1 1 Institute of Dermatology, Santa Maria della Misericordia University Hospital, Udine, Italy Key words: dermoscopy, differential diagnosis, general dermatology, inflammoscopy Citation: Errichetti E. Dermoscopy of inflammatory dermatoses (inflammoscopy): an up-to-date overview. Dermatol Pract Concept. 2019;9(3):169-180. DOI: https://doi.org/10.5826/dpc.0903a01 Accepted: June 2, 2019; Published: July 31, 2019 Copyright: ©2019 Errichetti. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The author has no conflicts of interest to disclose. Authorship: The author takes responsibility for this publication. Corresponding author: Enzo Errichetti, MD, MSc, Institute of Dermatology, Santa Maria della Misericordia University Hospital, Piazzale Santa Maria della Misericordia, 15, 33100 Udine, Italy. Email: enzoerri@yahoo.it In addition to its use in pigmented and nonpigmented skin tumors, dermoscopy is gaining apprecia- tion in assisting the diagnosis of nonneoplastic diseases, especially inflammatory dermatoses (inflam- moscopy). In this field, dermoscopic examination should be considered as the second step of a “2-step procedure,” always preceded by the establishment of a differential diagnosis on the basis of clinical examination. In this paper, we sought to provide an up-to-date overview on the use of dermoscopy in common inflammatory dermatoses based on the available literature data. For practical purposes, the analyzed dermatoses are grouped according to the clinical presentation pattern, in line with the 2-step procedure principle: erythematous-desquamative and papulosquamous dermatoses, papulokeratotic dermatoses, erythematous facial dermatoses, sclero-atrophic dermatoses, and miscellaneous.  ABSTRACT 170 Review | Dermatol Pract Concept 2019;9(3):1 dermoscopic analysis): erythematous- desquamative and papulosquamous der- matoses, papulokeratotic dermatoses, erythematous facial dermatoses, sclero- atrophic dermatoses, and miscellaneous. Erythematous- Desquamative and Papulosquamous Dermatoses Psoriasis Psoriasis is surely one of the dermatoses that benefits most from dermoscopic analysis as it usually displays a repetitive pattern, ie, uniformly distributed dotted vessels (histologically corresponding to dilated capillaries in regularly elongated dermal papillae) over a light or dull red background along with diffuse white scales (histologically corresponding to parakeratosis) (Figure 1A) [1]. Notably, psoriatic vessels are typically uniform in size, shape, and distance among each other [1,2]. In hyperkeratotic lesions, vascular structures may be poorly vis- regard, the use of noncontact polarized dermatoscopes is usually recommended as they preserve such findings; an inter- face fluid (eg, oil or gel) is sometimes required to enhance the visualization of structures covered by overlying scal- ing [1,2]. Of note, dermoscopic assessment of inflammatory diseases should be consid- ered as the second step of a “2-step pro- cedure,” always preceded by the estab- lishment of a differential diagnosis on the basis of clinical examination [1,2]. Indeed, such conditions often display only poorly specific dermoscopic find- ings that, however, may be useful if used in the context of a specific differential diagnosis [1,2]. This paper aims to provide an up-to- date overview on the use of dermoscopy in common inflammatory dermatoses based on the available literature data. For practical purposes, the analyzed der- matoses are grouped according to the clinical presentation pattern, in line with the 2-step procedure principle (ie, clini- cal differential diagnosis followed by Figure 1. Uniform dotted vessels and diffuse white scales in psoriasis (A). Dotted vessels dis- tributed in clusters and yellow scales and serocrusts in eczematous dermatitis (B). The typical Wickham striae of lichen planus; brownish dots are also visible around Wickham striae (C). Lichen nitidus typically reveals roundish, well-defined, white areas devoid of physiological skin markings (D). [Copyright: ©2019 Errichetti.] A C B D ible and scale removal or the use of a fluid interface may facilitate their visual- ization [1,2]. In addition, scale removal may also display tiny red blood drops, the so-called dermoscopic “Auspitz sign” [1,2]. Of note, vessels may sometimes appear as red globules (defined as round vessels having a diameter more than 0.1 mm) on dermoscopic exami- nation, especially on the legs (due to the higher hydrostatic pressure of this area) [1,2,4]. Both dotted and globular vessels look like dilated, elongated, and convoluted (bushy) capillaries under higher magnifications (×100-×400) [1,2,4]. While differentiating dotted ves- sels from globular vessels has not been found to be of any help in the diagnostic accuracy in psoriasis, a recent study showed that the presence of globular vessels in psoriatic lesions is a negative response predictor to narrowband ultra- violet B (Nb-Uvb) phototherapy [4]. The association of uniform dotted vessels on a red background and diffuse white scales has been found to display good diagnostic accuracy for psoriasis, with a sensitivity of 84.9% and a speci- ficity of 88.0% [5]. Indeed, although dotted/globular vessels and white scal- ing also characterize Bowen disease, in this condition vessels are more com- monly distributed in a focal/clustered pattern and are different in size, shape, and distance among each other [6]. In addition, the presence of uniform dot- ted vessels vs short, fine telangiectasias is helpful in differentiating psoriatic patches from superficial basal cell car- cinoma [7]. In this regard, a recent study introduced a dermoscopic diagnostic model for the differentiation of solitary psoriatic plaques from intraepidermal carcinoma and superficial basal cell car- cinoma, stating that the concomitant presence of red dots, a homogeneous vascular pattern, and a light red back- ground yields a diagnostic probability of 99% for psoriasis [7]. Importantly, uniform dotted/globu- lar vessels may also be seen in lichen Review | Dermatol Pract Concept 2019;9(3):1 171 fungoides show thin linear vessels alone or in combination with red dots, form- ing the so-called “spermatozoon-like” structures, while dermatitis typically lacks linear vessels, unless overtreated with topical steroids [13]. Lichen Planus The dermoscopic hallmark of lichen planus is represented by Wickham striae (Figure 1C), which histologically cor- respond to hypergranulosis [1,2]. In addition to their network-like appear- ance, Wickham striae may less com- monly display other morphologies on dermoscopy, including linear, “radial streaming,” annular, round, “leaf vena- tion” (delicate secondary striae branch- ing from the centered whitish venation, linked together at either end, mimick- ing the crystal structure of snow) and “starry sky” (clustered, follicular white dots) aspect [1,2]. Notably, Wickham striae are typically white, yet they may also appear yellow or blue, respectively, on palmoplantar areas and in dark- skinned patients [1,2]. Importantly, network-like white structures similar to Wickham striae may also be seen in scarring/resolving lesions of several dermatoses (pseudo- Wickham striae), eg, discoid lupus erythematosus, nodular scabies, and prurigo nodularis [1,2]. They are due to dermal fibrosis and may be distin- guished from Wickham striae on the basis of the vascular pattern as they usually show vessels that are signifi- cantly more dilated than those visible in Wickham striae [1,2]. Additional findings visible in active lesions include the following: (1) dotted, globular, and/or linear vessels, mainly detectable at the periphery of the lesion and less commonly showing a perifollic- ular or diffuse arrangement; (2) white/ yellow dots; and (3) pigmented struc- tures (dots, globules, and/or reticular or cloud-like areas) [1,2]. Although all the above-mentioned findings may sometimes coexist in a steroids by displaying telangiectatic ves- sels [1,2]. Eczematous Dermatitis Eczematous dermatitis consists of sev- eral distinct clinical entities that share the presence of spongiosis on histology, eg, atopic dermatitis, allergic contact dermatitis, stasis dermatitis, and astea- totic eczema [1,2]. The dermoscopic hallmarks of eczematous dermatitis include dotted vessels distributed in clusters or ran- domly (unspecific arrangement), corre- sponding to dilated capillaries in irregu- larly elongated dermal papillae, and yellow scales and serocrusts, resulting from hyperkeratosis and spongiosis/ exocytosis (Figure 1B) [1,2]. Hemor- rhages may also be seen as a result of intense itching [1,2]. Of note, the dermoscopic pattern of eczematous dermatitis varies accord- ing to the disease stage [1,2]. In detail, in acute phases yellow serocrusts and dotted vessels distributed in clusters or randomly are typically seen, while more or less uniform dotted vessels sur- rounded by a white halo are the main dermoscopic features in chronic phases (lichenification) [1,2]. Obviously, over- lapping pictures are often seen in clinical practice [1,2]. Importantly, some subtypes of eczematous dermatitis may display peculiar additional features. In par- ticular, stasis dermatitis often displays globular or glomerular vessels due to the presence of a higher hydrostatic pres- sure, chronic hand eczema commonly shows brownish-salmon-colored dots/ globules (representing spongiotic vesi- cles), and asteatotic eczema frequently reveals white scales having a double free edge (“rail-like” appearance) [1,2,10]. A case-control study has demon- strated that dermoscopy may support the differential diagnosis between chronic, resistant-to-treatment or relaps- ing eczema and patch-stage mycosis fun- goides [13]. In detail, patches of mycosis simplex chronicus and secondary lichen- ification [2]. Unlike psoriasis, however, in these conditions vessels are typically surrounded by a white halo due to the presence of hypergranulosis [2]. The dermoscopic features seen in specific subtypes of psoriasis do not dif- fer significantly [1,8]. In fact, the dermo- scopic pattern of the disease in specific body sites is identical to that of plaque psoriasis, with variations in the amount of scaling depending on the localization of the lesions [8]. In psoriatic balani- tis and inverse psoriasis, lesions lack scaling, but the typical vascular pattern of regularly distributed red dots is evi- dent on dermoscopic examination [6,8]. Little or absent scaling is also typical of guttate psoriasis as this form of pso- riasis is eruptive, thereby having little hyperkeratosis [9]. Conversely, in scalp or palmoplantar psoriasis, the thick hyperkeratotic surface of the plaques does not allow the visualization of the underlying vascular structures, which are highlighted after removal of the scales [8,10,11]. In pustular psoriasis, palmoplantar and generalized forms, yellow globules (pustules) and crusts are also visible along with dotted vessels and white scaling, while follicular pso- riasis is characterized by white follicular keratotic plugs surrounded by uniform dotted vessels [1,2]. The “red globular ring” pattern, with vessels distributed in a network- like arrangement, is another less com- mon (but specific) vascular pattern visi- ble in plaque-type psoriasis lesions [1,2]. As mentioned above, dermoscopy may also be helpful in treatment evalu- ation and monitoring. Apart from the negative predictive value of globular vessels when psoriasis is treated with Nb-Uvb phototherapy, it has been dem- onstrated that hemorrhagic dots are a positive predictive sign suggesting a favorable clinical outcome in psoria- sis treated with biological agents [12]. Finally, dermoscopy can reveal an other- wise not clinically evident skin atrophy following treatment with potent topical 172 Review | Dermatol Pract Concept 2019;9(3):1 visible as well [1,2,5]. Interestingly, an eczematous reaction may occur on the background of pityriasis rosea, espe- cially in atopic patients, with yellow serocrusts/scaling and clustered dot- ted vessels visible on dermoscopy along with the peripheral collarette scaling (Figure 2B) [1,2,5]. Pityriasis Lichenoides The term pityriasis lichenoides encom- passes a spectrum of diseases that includes 2 main variants, ie, pityria- sis lichenoides et varioliformis acuta (PLEVA) and pityriasis lichenoides chronica, although intermediate or over- lapping forms do exist [17,18]. Dermoscopic features of PLEVA and pityriasis lichenoides chronica differ significantly. Specifically, dermoscopic appearance of PLEVA varies accord- ing to the “lesion age,” with very early lesions commonly displaying a purpuric are more pronounced or deep in this district [16]. Dermoscopic assessment may be helpful in differentiating lichen nitidus from its main differential diagnoses, including follicular eczema and fric- tional lichenoid dermatosis, respectively characterized by roundish, equidistant, keratotic, whitish areas with blurry mar- gins and discrete, more or less defined, whitish areas with retention of the nor- mal skin furrows and regularly arranged dotted vessels [16]. Pityriasis Rosea Both the herald patch and secondary lesions of pityriasis rosea typically show a characteristic peripheral whitish scal- ing (“collarette” sign) as well as dotted vessels, which, unlike psoriasis, are dis- tributed in an irregular or focal pattern (Figure 2A); diffuse or localized yellow- ish orange structureless areas may be single lesion, dermoscopic patterns of lichen planus usually vary according to disease stage. [1,2]. Indeed, while early papules usually show subtle Wick- ham striae over a reddish background, mature lesions display well-represented Wickham striae and peripheral vessels. [1,2]. Both of such structures tend to fade over time, concomitantly to the gradual appearance of pigmented struc- tures (Figure 1C) [1,2]. In long-standing lesions, pigmentary findings are often the only visible clue [1]. Some clinical variants of lichen pla- nus may reveal peculiar features [1,14]. Relevant examples include annular lichen planus, in which Wickham striae appear as a peripheral annular white structure with capillaries or pigmen- tary findings (according to lesion dura- tion), and hypertrophic lichen planus, typically displaying follicular keratotic plugs [1,14]. In this last variant, Wick- ham striae are often not visible because they are covered by the overlying hyper- keratosis [1]. Apart from diagnostic purposes, dermoscopic examination may also be used to assess the likelihood of postin- flammatory pigmentation persistence, with homogeneous, structureless, and light brown areas devoid of granularity being correlated with a shorter dura- tion and granular pigmentation being associated with a longer course, and to monitor the evolution of lesions after therapy [15]. Lichen Nitidus Dermoscopic examination of lichen nitidus typically reveals roundish, well- defined, white areas devoid of physi- ological skin markings (Figure 1D) [16]. The absence of skin markings is a very relevant dermoscopic clue to recognize such a dermatosis as it is related to a quite characteristic histological finding, ie, flattening of the epidermis overlying the inflammatory infiltrate [16]. How- ever, lesions on the penis may retain skin markings, probably because they Figure 2. Dermoscopy of pityriasis rosea shows the characteristic peripheral whitish scaling (“collarette” sign). No vessels are seen (A); pityriasis rosea in an atopic patient displays yel- low serocrusts/scaling along with the peripheral whitish scaling collarette (B). Central amor- phous brownish crust surrounded by a peripheral scaling collarette and a purpuric halo is visible in a case of pityriasis lichenoides et varioliformis acuta (C). Dermoscopic examination of pityriasis lichenoides chronica reveals an orange structureless area along with nondotted vessels (linear-irregular and branching vessels), white scaling, and sparse dotted vessels (D). [Copyright: ©2019 Errichetti.] A C B D Review | Dermatol Pract Concept 2019;9(3):1 173 tinguish extrafacial discoid lupus ery- thematosus from subacute lupus erythe- matosus [1,2,19]. Papulokeratotic Dermatoses Porokeratosis The dermoscopic hallmark of all vari- ants of porokeratosis is the presence of a well-defined, annular, peripheral, white hyperkeratotic structure (“white track”) having 2 free edges which appears as similar to the outlines of a volcanic crater as observed from a high point (Figure 4A) [1]. Such a keratotic rim may be hyperpigmented in disseminated superficial actinic porokeratosis and in dark-skinned patients [1]. From a his- tological point of view, it corresponds to the “cornoid lamella.” In this regard, dermoscopy may be helpful even in treatment monitoring [1]. The center of the lesions is usually whitish or brownish and may exhibit circular and/or linear whitish and/or hyperpigmented tracks, blue-gray dots, and dotted, linear, or globular ves- sels [1]. Darier Disease and Grover Disease Because they have a strict histological similarity, Darier disease and Darier-like Grover disease share a similar dermo- keratoderma is typified by orange struc- tureless areas [1,2,11]. In erythrodermic stage, PRP features orange blotches and islands of nonerythematous (spared) skin displaying reticular vessels; unspe- cific whitish scaling and scattered dotted vessels over a reddish background may also be seen [18]. Dermoscopic assessment of lesions on elbows and knees in circumscribed juvenile PRP often displays whitish keratotic follicular plugs with a yellow peripheral keratotic ring, surrounded by an erythematous halo with linear and/ or dotted vessels; whitish scaling is also visible [2]. Palmoplantar keratoderma in this form of PRP shows the same aspect as the classic variants [11]. Subacute Lupus Erythematosus Subacute cutaneous lupus erythema- tosus is characterized by 2 constant dermoscopic findings, namely whitish scales (diffusely or peripherally distrib- uted) and a mixed vascular pattern (at least 2 types of vessels among dotted, linear-irregular, linear and branching vessels) over a pinkish-reddish back- ground (Figure 3B) [19]. Focally dis- tributed orange-yellowish structureless areas due to dermal hemosiderin depos- its may also be seen less commonly [19]. Unlike discoid lupus erythematosus, follicular plugs are typically not seen, and this finding may be helpful to dis- aspect (more or less diffuse hemorrhagic areas due to erythrocyte extravasation), mature lesions usually showing a cen- tral amorphous brownish crust (due to epidermal necrosis) (Figure 2C), and healing lesions often featuring a central white area (due to fibrosis) [1,2,17]. A rim of pinpoint and/or linear vessels with a targetoid aspect may be seen at the periphery of the lesions [1,2,17]. These vascular structures appear as dilated and convoluted vessels at higher magnification, with some of them show- ing a glomerular pattern or linear aspect [1,2,17]. In addition, a peripheral scal- ing collarette having an inner free edge is often evident in all the stages, espe- cially in mature (Figure 2C) and healing lesions [1,2,17]. On the other hand, pityriasis lichen- oides chronica typically displays orange- yellowish structureless areas (corresponding to hemosiderin deposits in the dermis due to erythrocyte extravasation) and nondotted vessels (including globular, linear-irregular, and/or branching ves- sels) (Figure 2D); diffuse and/or periph- eral whitish scaling, focally distributed dotted vessels, hemorrhagic spots, and hypopigmented areas are additional dermoscopic findings [9]. Of note, the presence of hypopigmented areas is more common in long-standing lesions, which often display focal postinflamma- tory hypopigmentation. Importantly, in dark-skinned patients, orangish areas are difficult to see [9]. Pityriasis Rubra Pilaris Dermoscopy has been found to be help- ful in supporting the diagnosis of several clinical manifestations of both classic pityriasis rubra pilaris (PRP) and cir- cumscribed juvenile PRP. In detail, papular lesions of classic PRP usually reveal round/oval yellowish areas surrounded by vessels of mixed morphology (ie, linear and dotted) (Fig- ure 3A) and often centered by central keratin plugs, whereas palmoplantar Figure 3. Pityriasis rubra pilaris features a roundish, yellowish area surrounded by vessels of mixed morphology (ie, linear and dotted) (A). Dermoscopy in subacute lupus erythema- tosus reveals white scales and a mixed vascular pattern (ie, dotted and linear vessels in this case; visualized more clearly in the box) over a pinkish-reddish background (B). [Copyright: ©2019 Errichetti.] A B 174 Review | Dermatol Pract Concept 2019;9(3):1 most typical dermoscopic findings of seborrheic dermatitis consist of dot- ted vessels in a patchy distribution and fine yellowish scales (in combination or not with white scales) [25], it is not uncommon to observe facial lesions displaying a different vascular pat- tern, ie, linear branching vessels (with or without dotted vessels) [1,2]. Such a vascular pattern is even more com- mon in scalp seborrheic dermatitis [1,2]. Additional, unspecific features of facial seborrheic dermatitis include follicular plugs, orange-yellowish areas, and whit- ish structureless areas [25]. Demodicosis Demodicosis is an underrecognized facial dermatosis whose clinical presen- tation may mimic several dermatoses, mainly including rosacea and seborrheic dermatitis [27]. The dermoscopic hallmark of all clinical subtypes are the so-called Erythematous Facial Dermatoses Rosacea Erythemato-telangiectatic subtype is the most studied variant of rosacea [25,26]. It typically features a quite constant and specific dermoscopic pattern, namely linear vessels characteristically arranged in polygonal networks (vascular poly- gons) (Figure 5A) [25,26]. Additional dermoscopic findings may be seen but are poorly specific, including rosettes, follicular plugs, white-yellowish scales, pigmentation structures, and dilated follicles [25,26]. Pustules and orange structureless areas, often associated with vascular polygons, are typically seen in papulopustular and granulomatous rosacea, respectively [1,2,25,26]. Seborrheic Dermatitis Although a study on facial inflamma- tory dermatoses concluded that the scopic pattern [20-22]. Indeed, both are typically characterized by a central yellowish-brownish area having a star- like, branched polygonal or round-oval shape, resulting from compact hyper- keratosis and exocytosis (due to acan- tholysis), and a peripheral white halo corresponding to acanthosis (Figure 4B) [20-22]. The same dermoscopic pattern is visible in BRAF-inhibitor-induced acantholytic dyskeratosis owing to their similar histological background [1]. On the other hand, spongiotic histologi- cal subtype of Grover disease displays whitish scaling over a reddish-yellowish background [22]. Dotted and/or linear/irregular ves- sels are additional findings visible in both Darier disease and Darier-like and spongiotic Grover disease [20-22]. Prurigo Nodularis The dermoscopic pattern of prurigo nodularis (both hyperkeratotic and excoriated lesions) consists of radially arranged whitish lines or peripheral whitish halo with some centrifugal coarse projections on a brownish and/ or reddish background, the so-called “white starburst pattern” (Figure 4C) [23]. In the center of the lesions, brown- reddish or brown-yellowish crusts (Fig- ure 4C), erosions, and/or hyperkeratosis or scales may also be seen [23]. Such a pattern is quite different from that of its main differential diagnoses, including hypertrophic lichen planus (see above), acquired reactive perforat- ing collagenosis (ARPC), and nodu- lar scabies [1,23,24]. Central round brownish-greenish/yellowish brown structureless area surrounded by a white keratotic collarette and an erythema- tous halo with or without dotted vessels (“trizonal concentric” pattern) is typi- cally seen in ARPC (Figure 4D), while nodular scabies usually features dotted vessels, sometimes associated with the presence of mites (“hang glider sign”) and/or burrows (“jet with condensation trails”) [1,23,24]. Figure 4. The typical white keratotic track having 2 free edges is visible in a case of porokera- tosis (A). Darier disease characteristically reveals a central star-like, yellowish area surround- ed by a peripheral white halo (B). The “white starburst” pattern (peripheral radial white striae over a reddish-brownish background) is visible in a case of prurigo nodularis; a central yellow crust is also present (C). Acquired reactive perforating collagenosis displays a central round brownish-greenish structureless area surrounded by a white keratotic collarette and an erythematous halo (“trizonal concentric” pattern) (D). [Copyright: ©2019 Errichetti.] A C B D Review | Dermatol Pract Concept 2019;9(3):1 175 The first 2 conditions display an indis- tinguishable dermoscopic pattern, which is typified by focal or diffuse orange structureless areas and well-focused linear or branching vessels, which are usually located over the orange areas (Figure 5D) [30]. Other possible find- ings include milia-like cysts, erythema, whitish lines or structureless areas, fol- licular plugs, dilated follicles, pigmenta- tion structures, and white and/or yellow scales [30]. On the other hand, even though leishmaniasis is a granulomatous der- matosis, orange structureless areas are visible only in a minority of patients (approximately 15% of cases) because they are covered by the frequent overly- ing epidermal changes (ie, ulcerations/ erosions, crusting, or hyperkeratosis/ scaling) [30-32]. According to the avail- able literature, white/yellow follicular keratotic plugs (previously called “yel- low tears”) and white peripheral pro- jections (“white starburst pattern”) are the most characterizing features [30-32]. Granuloma Faciale Despite its name, granuloma faciale is a chronic leukocytoclastic vasculitis and not a granulomatous disease [1,25]. The presence of dilated follicular openings has been reported as the most character- izing dermoscopic feature of this condi- tion [1,25]. Linear and/or branching dilated vessels are also commonly seen [1,25]. In addition, purpuric spots and orange structureless areas, histologically corresponding to erythrocyte extravasa- tion and hemosiderin dermal deposits, may also be observed [1,25,29]. Less common, unspecific findings include perifollicular whitish halo, pigmenta- tion structures, follicular plugs, yellow- ish scales, whitish streaks, and whitish- grayish structureless areas [1,25]. Granulomatous Facial Diseases The main granulomatous dermatoses of the face include sarcoidosis, lupus vul- garis, and cutaneous leishmaniasis [30]. “Demodex tails,” which are white-yel- lowish, protruding, follicular keratotic plugs due to the presence of a mixture of keratotic material and mites in the follicles (Figure 5B) [27]. “Demodex follicular openings,” which consist of round and coarse follicular openings containing white/yellow plugs sur- rounded by an erythematous halo, are also referred as typical of demodico- sis and may represent nonprotruding Demodex tails [27]. Other unspecific dermoscopic find- ings may be observed (ie, diffuse ery- thema, scaling, pustules, and reticular dilated vessels) and their prevalence var- ies according to the subtypes of demodi- cosis [27]. Discoid Lupus Erythematosus Dermoscopy of facial (and extrascalp in general) discoid lupus erythematosus reveals different features according to the disease stage [1,25,28]. Early lesions are typified by white scales and follicular findings, namely follicular red dots surrounded by whit- ish halos (“inverse strawberry” pattern) or follicular whitish-yellowish keratotic plugs (visible as white rosettes on polar- ized-light dermoscopy) over a more or less erythematous background (“straw- berry” pattern) (Figure 5C) [1,25,28]. Vessels of variable morphology (dotted, linear-irregular, and/or branching) may also be seen, especially at the periphery of the lesions [1,25,28]. On the other hand, late lesions display white structureless areas, pig- mentary structures, hair loss, and tel- angiectatic linear-irregular, branching vessels and/or dotted/glomerular vessels [1,25,28]. Importantly, intermediate- stage lesions may reveal a mixture of all the aforementioned features [1,25,28]. Less common dermoscopic findings include diffuse hyperkeratosis (hyper- trophic discoid lupus erythematosus), dilated follicles, and yellowish scales [1,25,28]. Figure  5. Erythemato-telangiectatic rosacea with its typical linear vessels arranged in po- lygonal networks (vascular polygons) (A). The so-called Demodex tails (white-yellowish, protruding, follicular keratotic plugs) are visible in demodicosis (B). White keratotic plugs over a reddish background are the typical dermoscopic features of active discoid lupus ery- thematosus (C). Dermoscopy of sarcoidosis reveals orange structureless areas with overlying focused linear vessels; white areas are also visible (D). [Copyright: ©2019 Errichetti.] A C B D 176 Review | Dermatol Pract Concept 2019;9(3):1 sclerotic and sclerotic lesions, thus underlining that such a dermoscopic clue is much more relevant and useful for active lesions than early inflamma- tory and late ones [33]. Mucosal (anogenital) lichen scle- rosus reveals the same features as the cutaneous lesions (especially bright white areas and well-focused vessels), apart from the lack of follicular kera- totic plugs [33]. Necrobiosis Lipoidica Dermoscopy of necrobiosis lipoidica lesions typically shows yellow-orange structureless areas (Figure 6C), due to the presence of granulomatous inflam- matory infiltrate and lipid deposits in the dermis, and well-focused vascular structures, whose morphology varies according to the disease stage, with dotted, globular, comma-shaped, and glomerular vessels more commonly seen in early stages or active lesional border, network-shaped, linear, and hairpin-like vessels more frequent in more developed (mature) lesions and branching-serpentine vessels being typi- cal of advanced lesions [30]. Of note, diameter of branching-serpentine ves- sels typically decreases from the center to the periphery of the lesion due to the more marked epidermal atrophy in central areas (Figure 6C) [30]. Additional less common and poorly specific dermoscopic findings include ulcerations, whitish-yellowish crusts, highlighting that lesions belonging to different clinical phases may display a dermoscopic (and histological) over- lap [33]. Lichen Sclerosus The hallmarks of cutaneous lichen scle- rosus are represented by keratotic fol- licular plugs, corresponding to follicular hyperkeratosis, and well-defined, bright white patches, resulting from superfi- cial fibrosis (Figure 6B) [33]. In addi- tion, scaling and hemorrhagic spots have been shown to be quite specific for lichen sclerosus when compared to morphea [33]. Less common features include erythematous areas, focused ves- sels (especially linear-irregular and dot- ted), crystalline structures, unfocused large purple vessels, yellowish areas, and pigmentary structures (reticular brown areas and brown dots) [33]. Even in cutaneous lichen sclerosus there may be a variability of dermo- scopic pattern according to the clini- cal disease stage, with erythematous areas and focused vessels being more common in inflammatory lesions and unfocused large purple vessels and yel- lowish areas being typical of atrophic stages, yet a dermoscopic overlap is possible as the prevalence of bright white areas does not differ significantly between inflammatory and sclerotic lesions [33]. Interestingly, follicular keratotic plugs have been found more commonly in clinically inflammatory- In addition, cutaneous leishmaniasis is often typified by vascular structures having a variable morphology, includ- ing hairpin, comma, glomerular, and/or corkscrew vessels [30-32]. Thrombotic vessels, yellowish hue, white scarring areas, milia-like cysts, pustules, and perilesional hypopigmented halo are further unspecific findings that may be seen [30-32]. Sclero-atrophic Dermatoses Morphea The most specific dermoscopic feature of morphea consists of white clouds, which are ill-defined dull white areas corresponding to deep dermal fibro- sis (Figure 6A); erythematous areas, focused vessels (especially linear-irreg- ular but also branching and dotted), crystalline structures, unfocused large purple vessels, yellowish areas, and pig- mentary structures (structureless brown areas, reticular brown areas, and brown dots) are additional findings [33]. Of note, dermoscopic features may vary according to the disease stage, with erythematous areas and focused ves- sels (especially linear-irregular) being indicative of inflammatory phases and unfocused large purple vessels typical of atrophic stages [33]. However, the prevalence of white clouds does not dif- fer significantly among inflammatory, sclerotic, and atrophic stages, thereby Figure 6. Morphea is characterized by dull white areas with blurry margins (“white clouds”) (A). Keratotic follicular plugs, white scales, and hemorrhagic spots over a white-pinkish background are visible in lichen sclerosus (B). Necrobiosis lipoidica: yellow-orange struc- tureless areas and branching-serpentine vessels whose diameter decreases from the center to the periphery of the lesion (C). [Copyright: ©2019 Errichetti.] A B C Review | Dermatol Pract Concept 2019;9(3):1 177 frequently seen in repigmenting or pro- gressing lesions than stable lesions [1]. Other possible features include intral- esional pigmentary islands, perilesional hyperpigmentation, reversed pigmen- tary network, reticular pigmentation, and telangiectasias [1]. Lichen Pigmentosus vs Ashy Dermatosis Both lichen pigmentosus and ashy der- matosis are characterized by pigmented dots (“peppering”) [38]. However, in the former dermatosis, dots are usually brownish and larger (Figure 9A) than those seen in the latter condition, which typically displays smaller and gray- bluish dots over a bluish background (Figure 9B) [38]. Such differences are the result of the different level of mela- nophages/melanin deposits (superficial dermis in lichen pigmentosus and deep papillary and reticular dermis in ashy dermatosis) [38]. Idiopathic Guttate Hypomelanosis vs Vitiligo Dermoscopy of idiopathic guttate hypomelanosis displays 2 main aspects, ie, the “cloudy sky-like” pattern (mul- tiple small areas coalescing into irregu- lar/polycyclic macules, with several white shades and both well- and ill- defined edges) and the “cloudy” pattern (well- or ill-defined roundish homo- geneous whitish areas) (Figure  8A), respectively more common in bigger and smaller lesions [37]. Notably, in both cases, patchy hyperpigmented net- work typically surrounds white areas (Figure 8A) [37]. On the other hand, well-demarcated, dense/glowing, white areas are the most common dermoscopic findings in vit- iligo (Figure 8B) [1]. Although not pres- ent in all lesions, white hairs and peri- follicular pigmentation (Figure 8B) are considered the most specific features of vitiligo, with the latter finding more whitish scaling, brownish reticular structures, and whitish structureless areas, with this last feature being more common in long-standing lesions, which are characterized by pronounced dermal fibrosis [30]. Miscellaneous Common Urticaria vs Urticarial Vasculitis Dermoscopy of common urticaria and urticarial vasculitis frequently shows a homogeneous erythematous back- ground (avascular areas), yet such a feature is less common in late lesions of urticaria vasculitis [2]. Reticular/ linear vessels may be present in both diseases, but they are significantly more frequent in common urticaria [2]. Con- versely, purple-red dots/globules, often on an orange-brown background, are highly indicative of urticarial vasculi- tis, as they are very rare in common urticaria [2]. Capillaritis (Pigmented Purpuric Dermatoses) vs Vasculitis The term capillaritis refers to a group of chronic, benign, cutaneous diseases that are characterized by extravasation of erythrocytes in the skin with conse- quent hemosiderin deposition, including Schamberg disease, Doucas-Kapetana- kis disease, Majocchi disease, Goug- erot–Blum syndrome, and lichen aureus [34,35]. All of them are typified by the presence of focused reddish purpuric dots and/or globules over a brownish- coppery background (Figure 7A); in addition, peripheral telangiectatic ves- sels and yellow scales/crusts are seen in Majocchi disease and Doucas-Kapeta- nakis disease, respectively [34,35]. Unlike capillaritis, dermoscopy of small-vessel skin vasculitis may reveal blue-gray patches and purpuric glob- ules/dots that are usually violaceous a n d b l u r r i e r ( F i g u r e   7 B ) b e c a u s e extravasated erythrocytes are located deeper [36]. Figure  7. Schamberg disease: focused reddish purpuric dots and globules over a coppery background (A). Unlike capillaritis, dermoscopy of small-vessel skin vasculitis reveals blur- rier violaceous purpuric globules (B). [Copyright: ©2019 Errichetti.] A B Figure  8. Idiopathic guttate hypomelanosis: well-defined roundish homogeneous whitish area (“cloudy” pattern) surrounded by patchy hyperpigmented network (A). Vitiligo: white areas and perifollicular pigmentation (B). [Copyright: ©2019 Errichetti.] A B 178 Review | Dermatol Pract Concept 2019;9(3):1 appearance may be seen in mastocy- toma, with the last 2 patterns more com- monly visible in regressing phases [1,40]. Granuloma Annulare The main dermoscopic clue (prevalence rate of 88.0%) of granuloma annulare is represented by unfocused vessels having a variable morphology (dotted, linear-irregular, and/or branching) over a more or less evident pinkish-reddish background (Figure 11A,B) [41]. Whit- ish (irregular or globular) and yellowish subtype [1]. In detail, urticaria pigmen- tosa typically reveals either a homo- geneous light-brown background or a coarse pigment network (Figure 10A), while telangiectasia macularis eruptiva perstans (TMEP) is mainly characterized by reticular or tortuous linear vessels on an erythematous/brownish base (Fig- ure 10B) [1]. A brownish network may sometimes be appreciated in TMEP [1]. Finally, diffuse/multifocal yellow-orange discoloration, diffuse light-brown dis- coloration, and brownish network-like Pityriasis Versicolor vs Gougerot- Carteaud Syndrome Distinguishing such conditions may be sometimes difficult on clinical grounds, and dermoscopy may provide some clues to facilitate their differential diag- nosis [1,39]. In particular, pityriasis versicolor is characterized by fine whit- ish scales localized in the skin furrows and a brownish background, while Gougerot-Carteaud syndrome typically shows fine whitish scaling associated with brownish, homogeneous, more or less defined, polygonal, flat glob- ules separated by whitish/pale striae creating a cobblestone appearance or brownish areas presenting a “sulci and gyri” pattern [1,39]. Balanitis According to a recent study, dermo- scopic examination may provide useful information on common forms of bala- nitis [6]. In particular, psoriatic bala- nitis and Zoon balanitis are the most recognizable forms, with the former being characterized by homogeneous dotted vessels distributed in a uniform pattern and the latter typically display- ing focal or diffuse orange areas along with focused linear curved vessels [6]. On the other hand, cottage cheese-like structures (representing sparse white coating corresponding to Candida yeast colony growth) showed a strong cor- relation with candidal balanitis [6]. All the above-mentioned forms of balanitis may be distinguished from erythroplasia of Queyrat, which features glomerular vessels distributed in a focal or diffuse pattern [6]. Notably, differentiating dot- ted from globular vessels on hand-held dermoscopic examination may be chal- lenging [6]. However, in erythroplasia of Queyrat, vessels are typically more heterogeneous in shape, size, and dis- tance among each other [6]. Mastocytoses Dermoscopic features of cutaneous mas- tocytoses vary according to the disease Figure  10. Coarse brownish network in urticaria pigmentosa (A). Telangiectasia macu- laris eruptiva perstans reveals tortuous linear vessels on a brownish base (B). [Copyright: ©2019 Errichetti.] A B Figure 11. In both “palisading granuloma” and “interstitial” histological variants of granu- loma annulare, dermoscopy shows unfocused vessels having a variable morphology (dotted, linear-irregular, and/or branching) over a more or less evident pinkish-reddish background (A,B). However, the former variant also features yellowish orange areas (A). [Copyright: ©2019 Errichetti.] A B A Figure 9. Brownish dots in lichen pigmentosus (A). In ashy dermatosis dots are smaller and bluish (B). [Copyright: ©2019 Errichetti.] B Review | Dermatol Pract Concept 2019;9(3):1 179 21. Errichetti E, Maione V, Pegolo E, Stinco G. Dermoscopy: a useful auxiliary tool in the diagnosis of type 1 segmental Dari- er’s disease. Dermatol Pract Concept. 2016;6(2):53-55. 22. Errichetti E, De Francesco V, Pegolo E, Stinco G. Dermoscopy of Grover’s dis- ease: variability according to histological subtype. J Dermatol. 2016;43(8):937-939. 23. Errichetti E, Piccirillo A, Stinco G. Der- moscopy of prurigo nodularis. J Derma- tol. 2015;42(6):632-634. 24. Suh KS, Han SH, Lee KH, et al. Mites and burrows are frequently found in nodular scabies by dermoscopy and histopathology. J Am Acad Dermatol. 2014;71(5):1022-1023. 25. Lallas A, Argenziano G, Apalla Z, et al. Dermoscopic patterns of common facial inflammatory skin diseases. J Eur Acad Dermatol Venereol. 2014;28(5):609-614. 26. Lallas A, Argenziano G, Longo C, et al. Polygonal vessels of rosacea are high- lighted by dermoscopy. Int J Dermatol. 2014;53(5):e325-327. 27. Segal R, Mimouni D, Feuerman H, Pa- govitz O, David M. Dermoscopy as a diagnostic tool in demodicidosis. Int J Dermatol. 2010;49(9):1018-1023. 28. Lallas A, Apalla Z, Lefaki I, et al. Der- moscopy of discoid lupus erythematosus. Br J Dermatol. 2013;168(2):284-288. 29. Jardim MML, Uchiyama J, Kakizaki P, Valente NYS. Dermoscopy of granuloma faciale: a description of a new finding. An Bras Dermatol. 2018;93(4):587-589. 30. Errichetti E, Stinco G. Dermatoscopy of granulomatous disorders. Dermatol Clin. 2018;36(4):369-375. 31. Taheri AR, Pishgooei N, Maleki M, et  al. Dermoscopic features of cuta- neous leishmaniasis. Int J Dermatol. 2013;52(11):1361-1366. 32. Yücel A, Günasti S, Denli Y, Uzun S. Cu- taneous leishmaniasis: new dermoscopic findings. Int J Dermatol. 2013;52(7):831- 837. 33. Errichetti E, Lallas A, Apalla Z, Di Stefani A, Stinco G. Dermoscopy of morphea and cutaneous lichen sclerosus: clini- copathological correlation study and comparative analysis. Dermatology. 2017;233(6):462-470. 34. Zalaudek I, Ferrara G, Brongo S, et al. Atypical clinical presentation of pig- mented purpuric dermatosis. J Dtsch Dermatol Ges. 2006;4(2):138-140. 35. Zaballos P, Puig S, Malvehy J. Der- moscopy of pigmented purpuric der- matoses (lichen aureus): a useful tool 8. Lallas A, Apalla Z, Argenziano G, et al. Dermoscopic pattern of psoriatic lesions on specific body sites. Dermatology. 2014;228(3):250-254. 9. Errichetti E, Lacarrubba F, Micali G, Piccirillo A, Stinco G. Differentiation of pityriasis lichenoides chronica from gut- tate psoriasis by dermoscopy. Clin Exp Dermatol. 2015;40(7):804-806. 10. Errichetti E, Stinco G. Dermoscopy in differential diagnosis of palmar psoriasis and chronic hand eczema. J Dermatol. 2016;43(4):423-425. 11. Errichetti E, Stinco G. Dermoscopy as a supportive instrument in the differ- entiation of the main types of acquired keratoderma due to dermatological dis- orders. J Eur Acad Dermatol Venereol. 2016;30(12):e229-e231. 12. Lallas A, Argenziano G, Zalaudek I, et al. Dermoscopic hemorrhagic dots: an early predictor of response of psoriasis to bio- logic agents. Dermatol Pract Concept. 2016;6(4):7-12. 13. Lallas A, Apalla Z, Lefaki I, et al. Der- moscopy of early stage mycosis fun- goides. J Eur Acad Dermatol Venereol. 2013;27(5):617-621. 14. Güngör S, Topal IO, Göncü EK. Dermo- scopic patterns in active and regressive lichen planus and lichen planus variants: a morphological study. Dermatol Pract Concept. 2015;5(2):45-53. 15. Vázquez-López F, Maldonado-Seral C , L ó p e z - E s c o b a r M , P é r e z - O l i v a N. Dermoscopy of pigmented lichen planus lesions. Clin Exp Dermatol. 2003;28(5):554-555. 16. Errichetti E, Stinco G. Comment on “Der- matoscopic features of lichen nitidus.” Pediatr Dermatol. 2018;35(6):879-880. 17. Lacarrubba F, Verzì AE, Dinotta F, Scavo S, Micali G. Dermatoscopy in inflamma- tory and infectious skin disorders. G Ital Dermatol Venereol. 2015;150(5):521- 531. 18. Errichetti E, Piccirillo A, Stinco G. Der- moscopy as an auxiliary tool in the dif- ferentiation of the main types of erythro- derma due to dermatological disorders. Int J Dermatol. 2016;55(12):e616-e618. 19. Errichetti E, Piccirillo A, Viola L, Stinco G. Dermoscopy of subacute cutaneous lupus erythematosus. Int J Dermatol. 2016;55(11):e605-e607. 20. Errichetti E, Stinco G, Lacarrubba F, Micali G. Dermoscopy of Darier’s dis- ease. J Eur Acad Dermatol Venereol. 2016;30(8):1392-1394. orange (focally or diffusely distributed) areas represent the most common non- vascular findings [41]. Of note, der- moscopic appearance of granuloma annulare significantly varies according to its histological subtype, with a strict association between yellowish orange structureless areas and palisading gran- uloma histological variant (Figure 11A) as they are usually absent in lesions hav- ing an interstitial histological pattern (Figure 11B) [41]. References 1. Errichetti E, Stinco G. Dermoscopy in general dermatology: a practical overview. Dermatol Ther (Heidelb). 2016;6(4):471-507. 2. Errichetti E, Stinco G. The practical use- fulness of dermoscopy in general der- matology. G Ital Dermatol Venereol. 2015;150(5):533-546. 3. Errichetti E, Zalaudek I, Kittler H, et al. Standardization of dermoscopic termi- nology and basic dermoscopic param- eters to evaluate in general dermatology (non-neoplastic dermatoses): an expert consensus on behalf of the International Dermoscopy Society. Br J Dermatol. 2019 May 11. Epub ahead of print. doi: 10.1111/bjd.18125. 4. Errichetti E, Stinco G. Clinical and der- moscopic response predictors in psori- atic patients undergoing narrowband ultraviolet B phototherapy: results from a prospective study. Int J Dermatol. 2018;57(6):681-686. 5. Lallas A, Kyrgidis A, Tzellos TG, et al. Accuracy of dermoscopic criteria for the diagnosis of psoriasis, dermatitis, lichen planus and pityriasis rosea. Br J Derma- tol. 2012;166(6):1198-1205. 6. Errichetti E, Lallas A, Di Stefani A, et al. Accuracy of dermoscopy in distin- guishing erythroplasia of Queyrat from common forms of chronic balanitis: re- sults from a multicentric observational study. J Eur Acad Dermatol Venereol. 2019;33(5):966-972. 7. Pan Y, Chamberlain AJ, Bailey M, Chong AH, Haskett M, Kelly JW. Dermatoscopy aids in the diagnosis of the solitary red scaly patch or plaque-features distin- guishing superficial basal cell carcinoma, intraepidermal carcinoma, and psoriasis. J Am Acad Dermatol. 2008;59(2):268- 274. 180 Review | Dermatol Pract Concept 2019;9(3):1 40. Vano-Galvan S, Alvarez-Twose I, De las Heras E, et al. Dermoscopic features of skin lesions in patients with mastocytosis. Arch Dermatol. 2011;147(8):932-940. 41. Errichetti E, Lallas A, Apalla Z, Di Ste- fani A, Stinco G. Dermoscopy of gran- uloma annulare: a clinical and histo- logical correlation study. Dermatology. 2017;233(1):74-79. 38. Errichetti E, Angione V, Stinco G. Der- moscopy in assisting the recognition of ashy dermatosis. JAAD Case Rep. 2017;3(6):482-484. 39. Errichetti E, Maione V, Stinco G. Der- matoscopy of confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome). J Dtsch Dermatol Ges. 2017;15(8):836-838. for clinical diagnosis. Arch Dermatol. 2004;140(10):1290-1291. 36. Choo JY, Bae JM, Lee JH, et al. Blue- gray blotch: a helpful dermoscopic find- ing in optimal biopsy site selection for true vasculitis. J Am Acad Dermatol. 2016;75(4):836-838. 37. Errichetti E, Stinco G. Dermoscopy of idiopathic guttate hypomelanosis. J Der- matol. 2015;42(11):1118-1119.