Dermatology: Practical and Conceptual 44 Research | Dermatol Pract Concept 2019;9(1):11 Dermatology Practical & Conceptual Dermoscopic Features of Psoriasis, Lichen Planus, and Pityriasis Rosea in Patients With Skin Type IV and Darker Attending the Regional Dermatology Training Centre in Northern Tanzania Maitseo K. Nwako-Mohamadi1,2, John E. Masenga1,2, David Mavura1,2, Ola F. Jahanpour3, Eva Mbwilo4, Andreas Blum5 1 Regional Dermatology Training Centre, Kilimanjaro Christian Medical Centre, Moshi, Tanzania 2 Kilimanjaro Christian Medical University College, Moshi, Tanzania 3 School of Public Health, Department of Epidemiology and Biostatistics, Catholic University of Health and Allied Sciences, Mwanza, Tanzania 4 Safe Focus Laboratory, Arusha, Tanzania 5 Public, Private, and Teaching Practice of Dermatology, Konstanz, Germany Key words: dermoscopy, papulosquamous, dark skin, Tanzania, Africa Citation: Nwako-Mohamadi MK, Masenga JE, Mavura D, Jahanpour OF, Mbwilo E, Blum A. Dermoscopic features of psoriasis, lichen planus, and pityriasis rosea in patients with skin type IV and darker attending the Regional Dermatology Training Centre in Northern Tanzania. Dermatol Pract Concept. 2019;9(1):44-51. DOI: https://doi.org/10.5826/dpc.0901a11 Published: January 31, 2019 Copyright: ©2019 Nwako-Mohamadi et al. 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 authors have no conflicts of interest to disclose. Authorship: All authors have contributed significantly to this publication. Corresponding author: Maitseo K. Nwako-Mohamadi, Regional Dermatology Training Centre @KCMC, Longuo B, Moshi, Tanzania. Email: madireks@yahoo.com Background: Papulosquamous skin diseases can be challenging to diagnose, especially in dark skin. Dermoscopy is reported to be helpful, but few data are available on its use in skin type IV or darker. Objective: To describe dermoscopic features in plaque-type psoriasis (PP), lichen planus (LP), and pityriasis rosea (PR) patients attending the Regional Dermatology Training Centre in Moshi, Northern Tanzania, and to compare findings with published data. Methods: A descriptive cross-sectional study was conducted at a tertiary hospital from October 2016 to June 2017. Fifty-six patients with PP, 25 with LP, and 9 with PR were enrolled consecutively. Clini- cal diagnosis was confirmed with histopathology in 74.4%. Dermoscopic vascular and nonvascular features from 225 lesions were analyzed. Results: Of the 90 patients enrolled, 58.9% were male and the median age was 50 (interquartile range 32.8-60.0) years. In PP lesions, red dots were found in 64.2% and white scale in 45.5%. In LP lesions the background was violet in 45.5% and 58.2% revealed Wickham striae. In PR lesions a dull red background was found in 50.0%, white scale in 83.3%, but no vessels were detectable. Conclusion: Dermoscopy features in PP, LP, and PR in dark skin are mostly similar to those in light skin. ABSTRACT Research | Dermatol Pract Concept 2019;9(1):11 45 [6,8]. The NO treatment group was defined as no topical treatment in the last 4 weeks or none at all; no systemic treat- ment was defined as no systemic corticosteroids in the last 4 weeks, no methotrexate in the last 3 months, or no systemic treatment at all [6,8]. Patients who had mucous membrane or nail lesions only, and those with atypical clinical appearance and refused biopsy, were excluded. Patient characteristics included sex, age, diagnosis, treat- ment status, anatomical site, Fitzpatrick skin type [12], and lesion morphology. The skin color was assessed at a non–sun- exposed area (right upper medial arm). Dermoscopic images of active lesions were taken using polar light mode in a handyscope (Fotofinder, Bad Birnbach, Germany) coupled with an iPhone 6 (8 megapixels, 1334 × 750 pixel resolution at 326 pixels/inch; Apple Inc., Cupertino, CA, USA). In any particular person, lesions were chosen (if present) from 6 different sites, ie, scalp, face, trunk/limbs, intertriginous areas (axilla, inframammary, or groin), palms/ soles, and knees/elbows [7]. Vascular features (background color, vessel morphology, vessel distribution/pattern) and nonvascular features (scale color, scale distribution, Wickham striae/pearly whitish structures, follicular disturbances, and pigmentary changes) were assessed [6,8]. Two examiners (M.K.N.-M. and R.M.) independently analyzed the dermo- scopic images and a third examiner (A.B.) was involved when no consensus was reached. Data capture and analysis were through SPSS version 20 (IBM SPSS Inc., Armonk, NY, USA).Continuous variables were summarized using medians and interquartile ranges (IQRs), while categorical variables were summarized using frequency and percentages. Results Ninety patients were enrolled (58.9% men and 41.1% women). The median age was 50 years (IQR 32.8-60). Patients with PP (n = 56) and LP (n = 25) were older (51 years [IQR 36.2-59.8] and 55 years [IQR 45.5-69]) than the patients with PR (n = 9) (19 years [IQR 7-30]). The demo- graphic characteristics according to the 3 skin diseases are shown in Table 1. In patients with PP, 148 lesions were assessed. The major- ity of the lesions (64.2%) were from the trunk and limbs, fol- lowed by elbows/knees (15.3%), scalp (13.5%), palmoplan- tar (8.8%), face (7.4%), and intertriginous sites (6.1%). In the patients with LP, 55 lesions were examined and the majority (67.3%) were from the trunk or limbs. In the PR patients, 54.5% of the 22 lesions were located on the trunk and limbs. Dermoscopic Features in PP The most common features of the 148 PP lesions were light red background (43.9%), red dotted vessels (64.2%), regu- Introduction and Background Plaque-type psoriasis (PP), lichen planus (LP), and pityriasis rosea (PR) are common skin diseases and may have a nega- tive impact on quality of life [1]. The clinical diagnosis can be challenging; sometimes a biopsy is needed, thus delaying the diagnosis and correct treatment [2]. Moreover, erythema often observed in these papulosquamous conditions may be masked in a dark-skin population [3,4]. In general, misdiag- nosis is reported in up to 32% of papulosquamous diseases but may be even higher in patients with dark skin [5]. Dermoscopy as a noninvasive diagnostic tool can help to diagnose without the need of a biopsy [6]. However, few data are available so far about its use and impact in inflamma- tory skin diseases in patients with skin type IV or darker [6]. Published data about dermoscopy on inflammatory lesions, so-called inflammoscopy, is mainly from countries with Caucasian or Asian patients, but only a few articles describe their patients’ skin type [7,8]. Thus, there is little knowledge regarding dermoscopic features in papulosquamous condi- tions in patients with dark skin (Fitzpatrick IV or darker) so far. A higher degree of dyspigmentation and less noticeable erythema has been described in psoriasis lesions in dark skin because of poorly visible dermal vessels [4,6]. In LP, a viola- ceous color is helpful as a diagnostic feature in lighter skin but it is less visible in darker skin, and therefore it is still not evident whether dermoscopy could be helpful here [9]. The aim of this descriptive study was to describe dermo- scopic features in PP, LP, and PR lesions in a clinical setting where most of the patients had Fitzpatrick type IV or darker skin and to compare the results with the present literature. Methods This hospital (tertiary)-based descriptive cross-sectional study was conducted at the Regional Dermatology Train- ing Centre outpatient department, Kilimanjaro Christian Medical Centre in Moshi, Northern Tanzania, from October 2016 to June 2017. The study received approval from the Kilimanjaro Christian Medical University College research and ethics committee and was conducted in accordance with the Helsinki Declaration, and written informed consent was obtained from participants. All patients with clinical diagnoses of PP, LP, and PR were enrolled consecutively. Clinical diagnosis was guided by standard descriptions [9–11]. A biopsy was performed wherever possible and in all cases of any atypical presenta- tion. Patients who were not receiving any treatment as well as those receiving treatment were enrolled. The ON treatment group included topical treatment (eg, steroids, salicylic acid, calcipotriene, or crude coal tar) or oral medication (steroids for at least 1 month or methotrexate for at least 3 months) 46 Research | Dermatol Pract Concept 2019;9(1):11 10; 47.6%). Among the 12 palmoplantar lesions the 2 most common colors were light and dark red (both at 47.6%). Red dots were seen at intertriginous sites (n = 8; 88.9%), scalp (n = 15; 75%), elbows/knees (n = 15; 71.4%), trunk/limbs (n = 46; 62.2%), palmoplantar (n = 7; 53.8%), and face (n = 4; 36.4%). The most common distribution was regular across all sites, seen in intertriginous sites (n = 7; 77.8%), trunk/ limbs (n = 36; 48.6%), palmoplantar (n = 6; 46.2%), scalp (n = 9; 45.0%), elbows/knees (n = 8; 38.1%), and face (n = 3; 27.3%). White scales were seen in face (n = 6; 54.5%), elbows/knees (n = 15; 71.4%), trunk/limbs (n = 58; 78.4%), intertriginous sites (n = 7; 77.8%), palmoplantar (n = 11; 84.6%), and scalp (n = 17; 85%). The scale distribution was mostly patchy across all the body sites, ranging between 55% lar vessels (46.6%), white scales (77.0%), patchy scale dis- tribution (55.4%), and pigmentary changes (56.8%), while pearly white structures (PWS) (100%) or follicular changes (79.9%) were not observed. Differences between the NO and the ON treatment group were less than 10% with the exception of more regular vessels in the ON compared with the NO treatment group (51.8% vs 40.0%), no follicular changes (86.7% vs 70.8%), and no pigmentary changes (48.2% vs 36.9%) (Table 2). Dermoscopy features were stratified according to various body sites. Dull red was the most common background color in face (n = 8; 72.7%), intertriginous areas (n = 5; 55.6%), and scalp (n = 9; 45.0%), while light red was more often found in trunk/limbs (n = 37; 50.0%) and elbows/knees (n = Table 1. Characteristics of PP, LP, and PR Patients (and Lesions) at Regional Dermatology Training Centre, Northern Tanzania (N = 90; 225 Lesions) Variable PP (n = 56); 148 Lesions LP (n = 25); 55 Lesions PR (n = 9); 22 Lesions Patients n (%) Lesions Scoped n (%) Patients n (%) Lesions Scoped n(%) Patients n (%) Lesions Scoped n (%) Sex Female 20 (35.7) 11 (44.0) 6 (66.7) Male 36 (64.3) 14 (56.0) 3 (33.3) Age (years) Median (IQR) 51.0 (36.2-59.8) 55 (45.5-69.0) 19 (7.0-30.0) <20 4 (7.1) 1 (4.0) 6 (66.7) 20-39 13 (23.2) 4 (16.0) 2 (22.1) 40-59 25 (44.6) 11 (44.0) 1 (11.1) 60-79 12 (21.4) 6 (24.0) ≥80 2 (3.6) 3 (12.0) Fitzpatrick skin type Type IV 3 (5.4) 10 (6.8) Type V 11 (19.6) 42 (28.4) 10 (40.0) 20 (36.4) 4 (44.4) 10 (45.5) Type VI 42 (75.0) 96 (64.9) 15 (60.0) 35 (63.6) 5 (55.6) 12 (54.5) Treatment status ON treatment 37 (66.1) 83 (56.1) 17 (68.0) 36 (65.5) 2 (22.2) 4 (16.7) NO treatment 19 (33.9) 65 (43.9) 8 (32.0) 19 (34.5) 7 (77.8) 18 (83.3) Body site Scalp 20 (13.5) 1 (1.8) Face 11 (7.4) 2 (3.6) 3 (13.6) Intertriginous 9 (6.1) 3 (5.5) 5 (22.7) Trunk/limbs 74 (50.0) 37 (67.3) 12 (54.5) Palms/soles 13 (8.8) 0 (0) 1 (4.5) Knees/elbows 21 (14.2) 12(21.8) 1(4.5) Lesion morphology Macule/patch 70 (47.3) 19 (34.5) 19 (86.4) Papule 5 (3.4) 14 (25.5) 2 (9.1) Plaque 73 (49.3) 22 (40.0) 1 (4.5) Research | Dermatol Pract Concept 2019;9(1):11 47 major pigmentary changes in patches (n = 3; 60%) and papules (n = 2; 33.3%). Plaques showed brown dots and patches (n = 2; 22.2%), gray dots and patches (n = 2; 22.2%), and a mix of brown and gray dots and patches (n = 2; 22.2%). (n = 5). Patchy scale distribution was found of in 60% of patches (n = 3) and in 44.4% of plaques (n = 4). PWS were seen in 83.3% of papules (n = 5), 88.9% of plaques (n = 8), and 40% of patches (n = 2). Gray dots and patches were the in scalp lesions (n = 11) to 69.2% in palmoplantar lesions (n = 9). Pigmen- tary and follicular changes were similar across different anatomical sites. Seventy-four (50.0%) of the PP lesions were located on the trunk and limbs and were stratified according to type of lesions: 34 were patches (45.9%), 1 p a p u l e ( 1 . 4 % ) a n d 3 9 p l a q u e s (52.7%). The main background color was light red in 15 patches (44.1%) and 22 plaques (56.4%), followed by dark red in 9 patches (26.5%) and 14 plaques (35.9%). Red dots were seen in 29 plaques (74.4%) and in 16 patches (47.1%) (Figure 1A). There was regular distribution of vessels in 22 plaques (56.4%) and 13 patches (38.2%). White scales were seen in 23 patches (67.6%) and in 34 plaques (87.2%). Patchy scale distribution was found in 15 patches (44.1%) and in 21 plaques (53.8%). Dermoscopic Features in LP The most common features of the 55 LP lesions were pigmentary changes (69.1%), PWS (58.2%), and a violet background (45.5%), while vessel mor- phology and pattern (each 80.0%), scales (65.5%), or follicular changes (67.3%) were not observed. More than 10% differences between the NO and the ON treatment group were observed, being in the violet background color (75.0% vs 28.6%), no scales (50.0% vs 74.3%), PWS (75.0% vs 48.6%), and no follicular disturbance (90.0% vs 54.3%) (Table 3; Figure 1B). In addition, 20 lesions of the NO treatment group were stratified accord- ing to lesion type (5 patches, 6 pap- ules, and 9 plaques). The most com- mon background color was violet in all lesion types (6 papules [100%], 7 plaques [77.8%], and 2 patches [40%]). Yellow color was seen only in patches (n = 2; 40%). Linear vessels were observed in 33.3% of papules (n = 2), in 11.1% of plaques (n = 1), and in none of patches. Also, none of the papules had scales. White scales were observed in 80.0% of patches (n = 4) and 55.6% of plaques Table 2. Dermoscopic Features in PP Lesions at Regional Dermatology Training Centre, Northern Tanzania (n = 148 Lesions) Variable NO Treatment (n = 65) n (%) ON Treatment (n = 83) n (%) Total (n = 148) n (%) Background color Light red 30 (46.2) 35 (45.2) 65 (43.9) Dull red 25 (38.5) 34 (41.0) 59 (39.9) Others 10 (15.4) 14 (13.8) 24 (16.2) Vessel morphology No vessels 26 (40.0) 27 (32.5) 53 (35.8) Red dots 39 (60.0) 56 (67.5) 95 (64.2) Vessel pattern No vessels 26 (40.0) 27 (32.5) 53 (35.8) Regular 26 (40.0) 43 (51.8) 69 (46.6) Patchy 13 (20.0) 13 (15.7) 26 (17.6) Scale color No scale 10 (15.4) 9 (10.8) 19 (12.8) White 48 (73.8) 66 (79.5) 114 (77.0) Others 7 (10.8) 8 (9.5) 15 (10.2) Scale distribution No scale 10 (15.4) 9 (10.8) 19 (12.8) Diffuse 19 (29.2) 18 (21.7) 37 (25.0) Patchy 33 (50.8) 49 (59.0) 82 (55.4) Others 3 (4.6) 7 (8.5) 10 (6.8) PWS No PWS 65 (100) 83(100) 148 (100) PWS present 0 (0) 0 (0) 0 (0) Follicular changes No changes 46 (70.8) 72 (86.7) 118 (79.7) Comedo-like opening 3 (4.6) 4 (4.8) 7 (4.7) Perifollicular hyperpigmentation 4 (6.2) 2 (2.4) 6 (4.1) Perifollicular hypopigmentation 6 (9.2) 3 (3.6) 9 (6.1) Milia-like cysts 2 (3.1) 1 (1.2) 3 (2.0) Others 4 (6.2) 1 (1.2) 5 (3.4) Pigmentation No pigmentary changes 24 (36.9) 40 (48.2) 64 (43.2) Brown dots and patches 14 (21.5) 10 (12.0) 24 (16.2) Gray dots and patches 11 (16.9) 19 (22.9) 30 (20.3) Mix of gray and brown 16 (24.6) 14 (16.9) 30 (20.3) 48 Research | Dermatol Pract Concept 2019;9(1):11 Discussion Dermoscopic features in PP, LP, and PR were observed to differ between these skin diseases in patients with skin type IV and darker (Table 5). Compared to the literature, these findings were mostly similar to lighter skin types (I-III) (Fig- ure 1, D-F), but in lower frequencies. Among patients with PP, red dots were seen in 64.2% of lesions in con- trast to Lallas et al [7], who described them in 97.1% (Figure 1E). A light red background with regularly distributed dotted vessels and white diffuse scales is reported to help in the diagnosis of psoriasis with 80%-88% specificity and 84.9%-87.8% sensitivity as stud- ied in Caucasian patients [6,13]. In this study, the same features were present, although in lower percentages, ie, a light red background in 43.9%. Regular ves- sels were seen in 46.6% compared to 63%-100% [7,13], white scale in 77% vs 64.7%-87.5% [7,8], and diffuse scale in 25% vs 44.6%-60% [7,14]. A pos- sible explanation could be that in darker skin, the red background and vessels are not easily visible compared to patients with a lighter skin type. The majority of psoriasis lesions had white scales, in agreement with the lit- erature, but most had a patchy distribu- tion in contrast to a diffuse distribution reported in most studies [6,8]. In addi- tion, we found white scales in 77.8% of intertriginous lesions compared to 13.2% in another study [7]. With these contrasting results, further research might be of help. The ON and NO treat- ment groups showed features in similar proportions except for vessel distribu- tion, follicular changes, and pigmentary changes, suggesting that dermoscopy can be of use in diagnosis of psoria- sis even for patients who are receiving treatment. The type of lesion also seems to affect features, with the expected fea- tures seen more in plaques compared to patches (eg, red dots [74.5% vs 47.1%]; white scale [87.2% vs 67.6%]). This is between the NO and the ON treatment group were observed in the dull red background color (55.6% vs 25.0%), white scales color (77.8% vs 100%), patchy scales distribution (27.8% vs 75%), peripheral scales distribution (38.9% vs 25%), and mix of brown and gray pigmentation (each 38.9% vs 25%) (Table 4; Figure 1C). Dermoscopic Features in PR The most common features of the 22 PR lesions were pigmentary changes ( 6 3 . 6 % ) , a d u l l r e d b a c k g r o u n d (50.0%), white scale color (81.8%), and patchy/peripheral scale distribu- tion (each 36.4%) No vessels, PWS, or follicular changes were seen in the PR lesions. More than 10% differences Figure 1. (A) Psoriasis plaque dermoscopy image showing dotted vessels and white scales in skin type VI. (B) Lichen planus patch dermoscopy image showing a violet background, Wickham striae (black arrow), and comedo-like openings (red arrow) in skin type V. (C) Pityriasis rosea dermoscopy image showing a dull red background and white scale in skin type VI. (D) Psoriasis plaque dermoscopy showing dotted vessels in skin type II. (E) Lichen planus dermoscopy image showing Wickham striae and dotted vessels in skin type II. (F) Pityriasis rosea der- moscopy image showing dotted vessels and peripheral scale. [Copyright: ©2019 Nwako- Mohamadi et al.] A B C D E F Research | Dermatol Pract Concept 2019;9(1):11 49 The white scale observed was similar in proportion to other studies (81.8% in our study and 85% by Lallas et al [6]), but in our patients patchy and peripheral distribution were in equal more dull/dark red in dark skin (Fig- ure 1C). Perhaps due to the dark pig- mentation, we observed no vessels, in contrast to Lallas et al, who reported red dots in 100% of their patients [6]. not surprising as plaques are expected to be more active. We noted nonvascular features as seen in Figure 1B to be more common in LP, in agreement with literature reports. A pearly white background (PWS) was the most common finding, in 58.2%, and this is similar to the 60% described by Chandravathi and colleagues [8]. PWS were also more often detectable in the nontreated lesions [15]. In the nontreated group, PWS were seen more in papules and plaques compared to patches, and this is expected as PWS correspond to compact orthokeratosis over areas of hypergranulosis and acanthosis [16]. No difference was found in the frequency of violet background in our population compared to the Caucasian population of Güngör et al [15] (45.5% vs 38%). Nonetheless a clear difference could be found in the NO vs the ON treatment group (75% vs 27.3%). The violet color might correspond to inflam- matory infiltrate, necrotic keratinocytes, and pigmentary incontinence over blood vessels [17]. In the NO treatment group, the violaceous color was seen more in raised lesions compared to patches, and this is expected as papules and plaques are expected to be more active in LP. Follicular changes were some of the less observed findings, with comedo- like openings at 16.4% similar to the 20% reported by Garg et al [18]. Pig- mentary changes were seen in 69.1% of lesions, and this could be related to more pigmentation in dark skin [9]. PWS are reported to be the most helpful dermoscopic feature in diagnosing LP, especially in untreated patients [6]. Our study confirms this observation in skin type IV and darker. In PR lesions the most common background color in our study was dull red (50%) compared to yellow (65%) among Caucasian patients, as reported by Lallas and colleagues [6]. This observation supports the idea that erythema could have various presenta- tions based on pigmentation, ie, more yellowish in light skin (Figure 1F) and Table 3. Dermoscopic Features in LP Lesions at Regional Dermatology Training Centre, Northern Tanzania (n = 55 Lesions) Variable NO Treatment (n = 20) n (%) ON Treatment (n = 35) n (%) Total (n = 55) n (%) Background color Light red 1 (5.0) 7 (20.0) 8 (14.5) Violet 15 (75.0) 10 (28.6) 25 (45.5) Yellow 2 (10.0) 6 (17.1) 8 (14.5) Brown 1 (5.0) 9 (25.7) 10 (18.2) Others 1 (5.0) 3 (8.6) 4 (7.3) Vessel morphology No vessels 16 (80.0) 28 (80.0) 44 (80.0) Red dots 0 (0) 3 (8.6) 3 (5.5) Lines 3 (15.0) 3 (8.6) 6 (10.9) Others 1 (5.0) 1 (2.8) 2 (3.6) Vessel pattern No vessels 16 (80.0) 28 (80.0) 44 (80.0) Patchy 1 (5.0) 4 (11.4) 5 (9.1) Peripheral 2 (10.0) 3 (8.6) 5 (9.1) Others 1 (5.0) 0 (0) 1 (1.8) Scale color No scale 10 (50.0) 26 (74.3) 36 (65.5) White 9 (45.0) 8 (22.8) 17 (30.9) Others 1 (5.0) 1 (2.9) 2 (3.6) Scale distribution No scale 10 (50.0) 26 (74.3) 36 (65.5) Diffuse 1 (5.0) 0 (0) 1 (1.8) Patchy 8 (40.0) 9 (25.7) 17 (30.9) Peripheral 1 (5.0) 0 (0) 1 (1.8) PWS No PWS 5 (25.0) 18 (51.4) 23 (41.8) PWS 15 (75.0) 17 (48.6) 32 (58.2) Follicular disturbance No disturbance 18 (90.0) 19 (54.3) 37 (67.3) Comedo-like opening 1 (5.0) 8 (22.8) 9 (16.4) Milia-like cysts 0 (0) 5 (14.3) 5 (9.1) Others 1 (5.0) 3 (8.6) 4 (7.2) Pigmentation No pigmentary changes 6 (30.0) 11 (31.4) 17 (30.9) Brown dots and patches 5 (25.0) 7 (20.0) 12 (21.8) Gray dots and patches 7 (35.0) 7 (20.0) 14 (25.5) Mix of gray and brown 2 (10.0) 10 (28.6) 12 (21.8) 50 Research | Dermatol Pract Concept 2019;9(1):11 Recommendations Further studies, probably with high-res- olution dermoscopy and bigger sample sizes, are needed especially in skin type IV and darker to further elaborate der- moscopic features in inflammatory skin diseases. Acknowledgments We thank Dr. Alex Mremi for reading the pathology slides, Ms. Madeline Kudra for helping with data input and speci- men preparation, Mr. George Semango cular features, predominant background colors, and pigmentary changes revealed differences between light and dark skin which could be explained by the different intensity of skin pigmentation. However, the dermoscopic diagnosis of PP, LP, and PR is possible in patients with dark skin and should encourage the use of der- moscopy in daily clinic for an early cor- rect diagnosis and to avoid unnecessary biopsies. Further studies, probably with higher-resolution dermatoscopes, are needed to further explore dermoscopic features in dark skin. proportion (36% each) while in the literature peripheral distribution was seen in 70% [6] (Figure 1C). Strengths This study explored dermoscopy fea- tures of PP, LP, and PR with focus on skin type IV and darker, thus adding to scientific data available on dark skin. Similar, but less frequent, dermoscopic features were found in skin type IV and darker compared to the Caucasian skin type. Our results may encourage the use of dermoscopy and further research among dark-skinned patients with pap- ulosquamous and other skin diseases. Limitations This study was performed in one center only and participants were recruited consecutively. This may lead to a selec- tion bias. However, the study was at a referral hospital that receives patients from several regions and thus the sam- ple would provide a good representation of the population having skin diseases in this area. Consecutive enrollment allowed us to capture a reasonable number of patients. We used a medium price range dermatoscope, and the dif- ference in resolution compared with pricier models might be of significance in dark skin. Conclusions Among dark-skinned patients (Fitzpat- rick type IV and darker) in PP, LP, and PR, dermoscopic findings were mostly the same as for skin types I-III as reported in the literature. The main findings in PP lesions were vascular, while in LP and PR the predominant findings were nonvascular. Only the frequencies of vas- Table 4. Dermoscopic Features in PR Lesions at Regional Dermatology Training Centre, Northern Tanzania (n = 22 Lesions) Variable NO Treatment (n = 18) n(%) ON Treatment (n = 4) n(%) Total (n = 22) n(%) Background color Light red 7 (38.9) 1 (25) 8 (36.4) Dull red 10 (55.6) 1 (25) 11 (50.0) Yellow 1 (5.5) 1 (25) 2 (9.1) Brown 0 (0) 1 (25) 1 (4.5) Vessels 0 (0) 0 (0) 0 (0) Scale color No scale 4 (22.2) 0 (0) 4 (18.2) White 14 (77.8) 4 (100) 18 (81.8) Scale distribution No scale 4 (22.2) 0 (0) 4 (18.1) Diffuse 2 (11.1) 0 (0) 2 (9.1) Patchy 5 (27.8) 3 (75) 8 (36.4) Peripheral 7 (38.9) 1 (25) 8 (36.4) PWS 0 (0) 0 (0) 0 (0) Follicular disturbance 0 (0) 0 (0) 0 (0) Pigmentation No pigmentary changes 7 (38.9) 1 (25) 8 (36.4) Brown dots and patches 2 (11.1) 2 (50) 4 (18.1) Gray dots and patches 2 (11.1) 0 (0) 2 (9.1) Mix of brown and gray 7 (38.9) 1 (25) 8 (36.4) Table 5. 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