Clinical value of dermoscopy in psoriasis

Dermoscopy is a noninvasive technique that has attracted increasing attention in the field of inflammatory skin diseases (such as psoriasis) in recent years.


| INTRODUC TI ON
Psoriasis is an immune-mediated chronic, recurrent, inflammatory skin disease that can occur in people of all ages and it affects the skin, nails, joints, and other sites.The typical clinical manifestations of psoriasis are erythematous papules and plaques covered with white scales.The prevalence of psoriasis is 0.09%-11.43%,and there are at least 100 million patients with psoriasis worldwide. 1The diagnosis and assessment of psoriasis are usually based on its typical clinical features.In uncertain cases, the diagnosis may be assisted using histopathology, which is an invasive test that is not acceptable to most patients.
Dermoscopy is a noninvasive technique that, in addition to magnifying and providing a light source, can render the cornified layer translucent to reveal the morphological details, such as the pigment and vascular structures in the epidermis and superficial dermis, that cannot be observed by the naked eye. 2 Dermoscopy has been used traditionally to diagnose and evaluate malignant skin tumors, 3 and in recent years, it has attracted increasing attention in the field of inflammatory skin diseases, such as psoriasis.As a noninvasive auxiliary diagnostic tool, dermoscopy is more acceptable to patients and has broad application prospects in the diagnosis, evaluation, and treatment of psoriasis. 4though the dermoscopic patterns of psoriasis have been preliminarily established, its clinical application in the diagnosis and extradiagnosis of psoriasis has not yet been elucidated.Furthermore there are no detailed reviews on the value of dermoscopy during the entire course of psoriasis.The aim of this paper was to provide an up-todate overview of the role of dermoscopy in the diagnosis, differential diagnosis, efficacy evaluation, monitoring, and prediction of psoriasis.

| Vessel pattern
The regular arrangement of red-dotted vessels is the most common vascular feature of psoriasis vulgaris, as seen using dermoscopy (Figure 1A,B).Blum et al. were the first to observe the symmetrically arranged pinpoint-like capillaries using dermoscopy. 5This vascular pattern has often been described as dotted vessels, [6][7][8][9][10] globular vessels, 10 red dots, 11,12 or red globules, 12 with corresponding histopathological features being the apical ends of vertically running dilated vessels that are distributed regularly in the club-shaped dermal papillae. 13,14[12]15,16 Although dotted vessels are the most common type of vascular pattern in psoriasis, they are not specific manifestations of psoriasis vulgaris.11][12]15 They have also been observed in some inflammatory skin diseases, such as erythroplasia and lichen planus. 17Although the shape, size, and distance of the vessels in these diseases are nonhomogeneous, the specificity of the regular distribution of vessels in the diagnosis of psoriasis has been found to be 100%. 11sed on locations of the lesion and skin phototypes, there are some differences in the vascular patterns.In the palmar and plantar areas, the frequency of dotted vessels has been found to be the lowest 8,9 and in the intertriginous areas (axilla, submammary, and groin), dotted vessels with regular distribution were more common, 8 whereas the vessels in the back were usually patchy. 12Patients with darker skin types (V or VI) were observed to be similar to those patients with lighter skin types (I-III); however, the frequency of specific vascular patterns was lower.In a study by Nwako-Mohamadi et al., red-dotted vessels were only observed in 64.2% of patients, regularly distributed vessels in 46.6% of patients, while 35.8% of patients had no obvious vascular changes. 8ng/hairpin-like vessels were first reported by Vazquez-Lopez et al.Under a dermoscope, 18 at a magnification of 10×, they appeared as round capillaries (red globules) arranged in irregular circles or rings with a beaded, lacelike capillary appearance (Figure 1C).
Histologically, this vessel pattern represents tortuous, plentiful, coiled, ectatic, and elongated capillaries within the thin, elongated, psoriatic dermal papillae with the different shapes of the vessels being due to the angle between the capillaries and epidermis. 14,18 psoriasis vulgaris, the frequency of the ring/hairpin-like vessels was found to be only 3.6% to 44.1% [9][10][11][12] ; however, the diagnostic specificity of the ring-like vessels was 94.6% to 100%, 11,19 and that of the hairpin-like vessels 91.9%. 19Therefore, the presence of ring/ hairpin-like vessels is significant in the diagnosis of psoriasis vulgaris.

| Scale pattern
White scale is one of the characteristic manifestations of psoriasis (Figure 1D), and its corresponding histopathological features are orthokeratosis and/or parakeratosis. 12The diagnostic specificity of white scales for psoriasis vulgaris was observed to be 83.8%, 19][10]12,15 of patients with psoriasis, under dermoscopy.The scales of the scalp (85% to 100%) 8,9,12 and palmar and plantaris (84.6% to 100%) 8,9 were found to be the most common, while scales on the face (54.4%), 8 intertriginous areas (13.2%-77.8%), 8,9and genitals (0.0%) 8,9 were relatively rare.12,15 Goliska et al. showed that the scale distribution was mainly patchy (55.6%) in the lesions lasting <5 weeks, and diffuse distribution was found in 64.5% of the older lesions.12 In some patients with psoriasis, yellow scales were observed with or without white scales (2.0% to 25.2%).6,7,9,10,12,15 Compared to younger patients, yellow scales were found to be more common in patients older than 50 years, possibly due to decreased skin turnover and increased orthokeratotic hyperkeratosis with age.15

| Other features
Light red is the most common background color for psoriasis (Figure 1E), and in children and adolescents, some researchers have described the background color as milky pink. 20This background color has been shown to correspond to the histopathological features, such as the thinning of the epidermis above the dermal papilla, dilatation of vessels in the dermal papilla and superficial dermis, and perivascular inflammatory cell infiltration. 13,14The sensitivity and specificity of the bright-red background were found to be 71.0% to 78.0% and 53.0% to 75.7%, respectively. 11,19morrhagic dots are dermoscopic manifestations of psoriasis (Figure 1F). 12Some researchers have also called it the Auspitz sign or bleeding foci, 21 which is significantly different from the dotted vessels of typical psoriasis.Bilgic et al. observed bleeding foci in 30% of patients with psoriasis, 15 which are observed commonly in the lower legs and forearms and may be related to blood extravasation caused by venous stasis and scratching. 12 conclusion, the most common dermoscopic findings of psoriasis vulgaris are dotted vessels in a regular arrangement over a light red background and white scales in a diffuse arrangement.In a study by Lallas et al., if all three features were present, psoriasis vulgaris was highly predicted, with a diagnostic specificity of 88.0% and a sensitivity of 84.9%. 6In conclusion, psoriasis vulgaris has a specific dermoscopic examination pattern, and there is little heterogeneity between the different lesion sites and skin phototypes.Dermoscopy is a tool of great clinical value in the diagnosis of psoriasis vulgaris.

| Nail psoriasis
Dermoscopy is highly accurate in the diagnosis of nail psoriasis.
Studies have shown that in nail psoriasis, the percentage of agreement between the clinical and dermoscopic examinations was 98%, and the percentage of agreement between histopathological and dermoscopic examinations was 88.88%. 22There were no significant differences between the agreement rate of clinical, dermoscopic, and histopathological examinations in the diagnosis of nail psoriasis.
Dermoscopy helps identify indications that are not easily visible to the naked eye.Studies have shown that pitting, subungual hyperkeratosis, salmon patch, and splinter hemorrhage were better visualized using a dermoscope than by clinical evaluation, 23,24 and Wannian et al. 23 pointed out that the pseudofiber sign and dilated hyponychial capillaries were only visible with the help of a dermoscope; thus, the dermoscopically evaluated Nail Psoriasis Severity Index (NAPSI) scores were significantly higher than the clinically evaluated NAPSI scores.In addition, Chauhan et al. 25 pointed out that psoriatic features could also be observed in the clinically unaffected nails of some patients under dermoscopy, suggesting that dermoscopy may be helpful in the early detection of nail psoriasis.
Dermoscopy is helpful in determining the affected area in nail psoriasis.Nail matrix involvement has been shown to manifest as deep pitting, red spots in the lunula, leukonychia, and so on, 22,23,[25][26][27][28][29][30][31][32] while nail bed involvement manifested as salmon patch/oil drop sign, onycholysis, splinter hemorrhage, and so on.(Table 1; Figure 2).Wannian et al. 23 and Yorulmaz et al. 26 observed filamentous red and black structures located in proximity to the cuticle or under the hyponychium along the distal free edge of the nail plate, which they called pseudofibrous structures.They believed that these were bare capillaries, suggesting the involvement of the nail bed.However, Ankad et al. 27 took the opposite view, arguing that they were adherent fibers, not capillaries.

| Other types of psoriasis
Palmoplantar psoriasis presents as hyperkeratotic, fissured plaques on the palms and soles, that may impair manual dexterity and walking. 34The most common dermoscopic feature of palmoplantar psoriasis has been shown to be diffuse white scales (60.5%-100.0%), 9,35,36ich may be associated with palmoplantar dryness and hyperkeratosis. 37Although red-dotted vessels (51.4%-90.9%) 9,35,36and lightred background (48.6%-59.8%) 35,36have also been shown to be common, they were less frequent than in other sites of the body, 9,35 possibly due to the thicker epidermis in the palmar and plantar regions, which hindered the visualization of underlying structures.Yu et al. 38 and Errichetti et al. 39 found that the dotted vessels in palmoplantar psoriasis may be distributed in a beaded pattern along the sulci cutis, which although they cannot always be observed have great diagnostic specificity and, therefore, and are considered an important indication for the diagnosis of palmoplantar psoriasis.
The scalp is one of the common sites of psoriasis.The vascular pattern of scalp psoriasis has been observed to be similar to that of psoriasis vulgaris, with the most common being the red dot/bulb vessels (94.0%).However, the twisted red loops were more common in patients with scalp psoriasis (57.8%) than in those with psoriasis vulgaris. 40ales on the scalp were observed more frequently than in other parts TA B L E 1 Dermoscopic manifestations and causes of nail psoriasis.

Affected area Dermoscopic manifestation Cause
Pittin 23,26,28,33 Nail matrix Large, deep, and irregularly distributed cupuliform depressions The keratinization of the stratum corneum of the proximal nail matrix is disrupted, and the columns of loose parakeratotic cells fall off, leading to deep and coarse pits.
Red lunula 25,31,33 Nail matrix The nail lunula appears spotted or erythematous in color Intermediate and ventral matrix involvement.
Leukonychi 31,33 Nail matrix The nail plates appear with white horizontal stripes, and the exterior surface is smooth in appearance Parakeratoses of the distal nail matrix, which prevents the normal desquamation of the underlying keratinocytes.
Beau's lines 31,33 Nail matrix Transverse grooves and ridges within the nail plate Intermittent inflammation of the proximal nail fold.
Onychorrhexis 31,33 Nail matrix Longitudinal ridging and splitting of the nails Corresponding longitudinal psoriatic lesions within the nail matrix.
Salmon patches/oil drop sign 26,28,33 Nail bed The yellowish-red discolorations appear as irregular translucent areas on the nail plate Parakeratotic lesions within the nail bed.
Onycholysis 26,28,33 Nail bed An erythematous border encircling a white onycholytic area Parakeratotic lesions at the level of the hyponychium lead to the separation of the nail plate from the nail bed, which allows air to enter inside.
Splinter hemorrhage 23,26,33 Nail bed Reddish-brown or purplish-black striae arranged in a longitudinal fashion, usually on distal parts of the nails The longitudinally running hyponychial capillaries rupture, causing the tracking of extravasated blood down the grooves beneath the nail plate.
Dilated hyponychial capillaries 25,27,28 Nail bed The bright red to dusky-colored dilated vessels are arranged parallel over the onychodermal band of the nail plate and surrounded by a prominent halo Dilated nail bed capillaries.Subungual hyperkeratosis 25,33 Nail bed The nail plate is raised off the nail bed ordinarily exhibited a white-silvery color The deposition and collection of cells under the nail plate that have not undergone desquamation. of the body, often being white, diffuse or patchy, and thick (Figure 3B). 12 addition, Kibar et al. 41 found that signet ring vessels and hidden hair may also be characteristics that support the diagnosis of psoriasis.
Erythrodermic psoriasis is an uncommon severe variant in which patients have been observed to develop coalescent erythema, scales, or exfoliation involving at least 75% of the body. 42Although there are few reports on the dermoscopic characteristics of psoriasis erythrodermic, only four cases have been reported, including two of adult patients, described by Errichetti et al. 43 and Sławińska et al. 44 and two of 3-year-old Caucasian twins, described by Campione et al. 45 They noted that the dermoscopic pattern of erythrodermic psoriasis may be consistent with that of psoriasis vulgaris, that is, regular red-dotted vessels over a light-red background with white scales.(Figure 3C).
Approximately one-third of patients with psoriasis develop psoriatic arthritis during their lifetime. 34Dermoscopy is also helpful in the diagnosis of psoriatic arthritis.Zabotti et al. 46 and Errichetti et al. 47 pointed out that some patients with psoriatic arthritis may have features of nail psoriasis, observed under dermoscopy.The presence of nail psoriasis has contributed to the early diagnosis of psoriasis arthropathica, with a sensitivity and specificity of 96.0% and 83.3%, respectively.Moreover, with the use of hand ultrasound, the specificity may be increased to 90.5%. 46

| Differential diagnosis of psoriasis vulgaris
Dermoscopy can provide a basis for the differential diagnosis of psoriasis vulgaris from lichen planus, pityriasis rosea, pityriasis rubra pilaris, and other diseases through the observation of the vascular morphology, vascular distribution, scale color, distribution of scales, and background color (Table 2; Figure 4).

| Differential diagnosis of nail psoriasis
According to the above specific dermoscopy patterns of psoriatic nails, dermoscopy may be used to help distinguish nail psoriasis from other nail diseases, such as onychomycosis, traumatic onycholysis, and allergic contact dermatitis due to artificial nails (Table 3; Figure 5).In addition, Zhu et al. 61  Artificial intelligence may also be used to improve the efficiency and accuracy of the diagnosis and differential diagnosis of nail disorders.

| Differential diagnosis of palmoplantar psoriasis
Highly overlapping clinical features often make the differentiation between palmoplantar psoriasis and palmoplantar eczema challenging (Figure 6A,C).Dermoscopy may help patients avoid invasive pathological biopsies and it has become an effective method for differential diagnosis.The most common vascular morphology of both palmoplantar psoriasis and palmoplantar eczema is dotted vessels, [35][36][37] but patchy distribution is common in palmoplantar eczema, which is different from the regular distribution of vessels observed in psoriasis.In addition, the characteristic features of palmoplantar eczema include a dull red or yellow background, 35,36 brown or orange dots and globules, [35][36][37][38] yellow crusts, 35,37 and yellow orange areas, 35,36 which are rare in psoriasis.In terms of scales, Errichetti et al. 37 believed that the color of the scales is the most useful clue for differential diagnosis.They also believed that yellow scales are common in palmoplantar eczema, whereas white scales are common in psoriasis.However, Yu et al. 38 noted that because of the local external use of drugs and other factors, the color of the scales is sometimes remarkably similar and cannot be used as a key differentiator between palmoplantar psoriasis and palmoplantar eczema.
Some studies have discussed the concept of "eczema in psoriatico."Eczema in psoriatico refers to patients with preexisting palmoplantar psoriasis presenting with coexistent allergic contact dermatitis and exhibiting a type 4 hypersensitivity pattern that leads to the maintenance or triggering of palmoplantar psoriasis.Overlapping dermoscopic features were observed in eczema in psoriatico, that is, a regular distribution of dotted vessels and a diffuse distribution of white-yellow scales on a light red to yellowish dull red erythema background (Figure 6B).However, the number of studies on eczema in psoriatico is small, and further research and verification are required. 36rmoscopy also helps distinguish palmar syphiloderm from palmar psoriasis (Figure 6B).Background color is an important differentiating factor. 39,65The background of palmar syphilis is typically orange, due to the deposition of hemosiderin in the dermis, which is markedly different from the light-red background observed in case of psoriasis.Meanwhile, the circular, thin, scaling edge surrounded by an erythematous halo has also been found to be an important diagnostic indicator of palmar syphiloderm, which is known as the "Biett sign." 65However, regularly distributed dotted vessels have been seen in both palmar syphiloderm and palmoplantar psoriasis; therefore, the vascular pattern cannot be used to distinguish them. 39

| Differential diagnosis of scalp psoriasis
Seborrheic dermatitis is observed most commonly on the scalp, nasolabial folds, ears, eyebrows, and chest.Although seborrheic dermatitis and psoriasis have some apparent clinical differences, when both conditions are localized only on the scalp, they can be difficult to distinguish with the naked eye. 66Dermoscopy may be useful here.The vascular patterns observed in seborrheic dermatitis are usually arborizing red lines, comma vessels, and atypical vessels.
The twisted red loops, which are similar to the pattern observed in psoriasis, have been relatively rare. 40,41,66,67While the incidence of white scales has been comparable in both lesions, the differentiation between them has been based mainly on vascular features. 40,66ing the abovementioned dermoscopic differential characteristics, a diagnostic method for discriminating scalp psoriasis and seborrheic dermatitis based on a deep learning model was developed, which exhibited a good sensitivity, specificity and area under curve, which outperformed the diagnoses of five dermatologists with various levels of experience. 67

| Assessment of severity
In terms of severity assessment, Carlesimo et al. 68 proposed the Vascular Psoriasis Area Severity Index(VPASI) score based on the Psoriasis Area Severity Index (PASI), which introduces vascular patterns and a finer partition of the body for a more sensitive and efficient quantification of psoriasis severity.However, Golińska et al. 12 and Bilgic et al. 15 pointed out that the PASI and BSA were not associated with any of the dermoscopic characteristics of psoriasis.

Dermoscopic manifestation
Nail psoriasis [26][27][28]33 Salmon patches Deep pitting Brownish band between the area of onycholysis and the normal nail Onychomycosis Spikes 27,56,57 : jagged edges with sharp whitish longitudinal indentations in the proximal portion of the onycholytic area Ruin pattern 27,58 : indentations on the ventral surface of the keratinocytes resulting in the accumulation of keratotic materials under the nail plate Longitudinal streak 27,56,59,60 : longitudinal streak on the nail plate, with changes in color ranging from bluish gray to black to whitish yellow Distal irregular termination 57,60,61 : the distal pulverization characteristic of the thickening of the nail plate in total dystrophic onychomycosis Traumatic onycholysis 27,28 The line of detachment of the nail plate from the nail bed is regular and smooth and is surrounded by a normal nail bed Allergic contact dermatitis due to artificial nails 62,63 Onycholysis with a dented border Periungual tissue damage Therefore, the utility of dermoscopy in the assessment of psoriasis severity needs to be demonstrated in further studies.
Dermoscopy of the nail area is also useful in assessing psoriasis severity.Studies have shown that nail plate thickening and crumbling, trachyonychia, transverse grooves, salmon patches, and subungual hyperkeratosis were associated positively with the NAPSI score. 26,31In addition, several indications, such as dilated capillary density, red spots in the lunula, transverse grooves, nail plate crumbling, trachyonychia, and splinter hemorrhage, have shown a positive correlation with systemic inflammation. 11,31Several studies have reported a positive correlation between the PASI and BSA with the NAPSI, and that nail involvement is correlated with the severity of skin diseases. 23,25,31Therefore, dermoscopic features of psoriatic nails are of clinical significance, not only for assessing the severity of nail conditions, but also for assessing systemic inflammation.

| Assessment of therapeutic effect
Several studies have shown that changes in the vascular patterns in psoriasis vulgaris can be used to evaluate treatment effects.
0][71] Moreover, the distribution density of the dotted/ globular vessels decreased gradually until there was a partial return to normal. 72,73The clinical symptom score shown a significant correlation with the diameter of the glomus observed under dermoscopy, 74 which suggested that the changes in the vascular pattern in the skin lesions may be used as an index to observe the effect of psoriasis treatment and the recovery of skin lesions.
However, the color and distribution of scales are generally not used in efficacy evaluations, possibly because the scale pattern is affected by scratching and clothing friction.Sometimes, researchers will select the site with fewer scales or scrape the scales for better observation of the vascular pattern. 75though studies evaluating the efficacy of nail dermoscopy are limited at present, they have shown promising clinical prospects.Iorizzo et al. 32 reported that a significant decrease in the number of visible capillaries after using calcipotriol ointment in the treatment of nail psoriasis showed a positive correlation with the degree of disease remission.Hashimoto et al. 76 reported that after the biological treatment of nail psoriasis, the symptom improvement was associated with a diffuse scaling of the nail plate, transverse step-like notches, thickened white-yellow nail plate, an elimination of the splinter hemorrhages of the nail bed, and the development of the erythematous borders of an onycholytic area.
Khashaba et al. 77 also found that, in patients with nail psoriasis, dermoscopic features, such as the thickened white-yellow nail plates, scaling of the nail plate, splinter hemorrhages of the nail bed, and distal onycholysis, improved after treatment with longpulse Nd:YAG laser.

| Prediction of therapeutic outcome
In recent years, several studies have shown that there is a correlation between the treatment outcome of psoriasis and the specific dermoscopic features, such as the hemorrhagic dots and blood vessel diameter, which makes dermoscopic features a potential predictor of the curative effect on psoriasis. 74,78,79der dermoscopy, the dotted vessels appear as densely packed punctate structures, while globular vessels are a special type of dotted vessel that appear as twisted vessels distributed in clusters, resembling glomeruli, 80 with a diameter larger than that of dotted vessels.The two look similar under handheld dermoscopy, 81 thus earlier studies did not consider the classification of dotted vessels by diameter to be of diagnostic significance. 82However, recent studies have shown that the globular vessels are associated with treatment resistance, while the dotted vessels predict better treatment outcomes in local treatments, such as calcipotriene plus betamethasone dipropionate aerosol foam, narrowband ultraviolet B phototherapy, and 650-microsecond 1064-nm Nd:YAG laser. 70,78,79Several studies have found that globular vessels are more likely to be observed in the legs, where the dotted vessels appear less frequently than in other parts of the body. 12,70,79May be due to a higher hydrostatic pressure due to microcirculation impairment in the legs, which leads to an increase in vessel permeability and consequent formation of a fibrin cuff around the capillaries, leading to tissue hypoxia and the release of inflammatory mediators.
However, the specific mechanism requires further study and verification. 79morrhagic dots are a common feature of psoriasis, observed under dermoscopy. 15,75Lallas et al. 75 found that, when using biological agents, the number and distribution of hemorrhagic dots may predict the treatment outcome 2-4 weeks ahead.The appearance of hemorrhagic dots may predict a favorable response to treatment, even before clinical improvement, thereby reducing the probability of error evaluation of the drug being invalid.
With regard to nail psoriasis, the study of Your et al. 30 pointed out that a better outcome may be predicted when transverse grooves, longitudinal ridges, and discoloration were observed under dermoscopy, suggesting that dermoscopy may be helpful in predicting the treatment outcome of nails psoriasis.
Vazquez-Lopez et al. 83 noted that in patients with chronic psoriasis treated with long-term topical steroids, the appearance of red linear vessels under dermoscopy may predict impending steroidinduced skin atrophy, helping detect lesions before macroscopic clinical manifestations and preventing atrophy from progressing to permanency.

| Monitoring and prediction of recurrence
In addition to the predictors of efficacy, specific dermoscopic features are monitoring factors for psoriasis and predictors of clinical recurrence.Several studies have shown that the dermoscopic and clinical manifestations of psoriasis vulgaris and nail psoriasis sometimes appear separate. 31,74,75,79The recovery of vessels or nails under dermoscopy is slower than clinical recovery; in other words, the dotted vessels and incompletely recovered surrounding skin may still be seen under dermoscopy when the clinical skin lesions have disappeared completely.With the persistence of dotted vessels under dermoscopy after treatment, the risk of disease recurrence is much higher than that in patients with complete vascular recovery.
Therefore, some researchers have proposed that the treatment of psoriasis achieve "dermoscopic healing" rather than "clinical remission" to ensure the retention of a stable curative effect for a longer time. 79Meanwhile, the recurrence of dotted vessels may predict clinical recurrence after recovery treatment with biological agents, 75 which may be helpful in monitoring psoriasis after recovery, the early identification of disease recurrence, and guidance of clinical treatment strategies.

| S TU DY LI M ITATI O N S
This review has many limitations.First, the literature on this topic was limited.Multicenter studies with larger sample sizes are

CO N FLI C T O F I NTE R E S T S TATE M E NT
None declared.

DATA AVA I L A B I L I T Y S TAT E M E N T
Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

E TH I C S S TATEM ENT
This article is based on previously conducted studies and does not contain any studies with human participants or animals performed by the author.

F I G U R E 3
Dermoscopic manifestations of other type of psoriasis.(A) Palmoplantar psoriasis; (B) Scalp psoriasis; (C) Erythrodermic psoriasis.

7 |
needed to provide more accurate information on the role of dermoscopy in the diagnosis and extra-diagnosis of psoriasis.Second, the terminology used to describe dermoscopic manifestations varies according to different researchers, especially in relatively new fields, such as the dermoscopic evaluation of nail psoriasis, and the prediction of the therapeutic outcome of psoriasis.The lack of consensus with regard to the terminology may cause confusion in clinical applications; therefore, standardization of terminology is necessary.CON CLUS ION Dermoscopy, as an economical, noninvasive, and rapid examination technique, has good clinical value in the diagnosis and differential diagnosis of psoriasis and shows great promise for severity assessment and efficacy prediction monitoring.However, due to the short development time, dermoscopy is still in the exploratory stage for the diagnosis and treatment of psoriasis, and further large-scale research is needed to establish the diagnostic criteria and explore the corresponding mechanism.ACK N OWLED G M ENTS This work was supported by the National Natural Science Foundation of China (81774309); Fifth Batch of National Research and Training Projects for Clinical Talents of Traditional Chinese Medicine (National Chinese Medicine Education Letter [2022] No. 1).We would like to thank Editage (www.editage.cn) for English language editing.