Dermoscopy of cutaneous granulomatous disorders: A study of 107 cases

Abstract

Background

Cutaneous granulomatous disorders (CGDs) can share some features, but an accurate assessment of various findings and their pattern can be useful in differentiating them. In addition to common dermoscopic findings for CGDs, some peculiar dermoscopic characteristics can be helpful in distinguishing them.

Objective

Herein, we aimed to evaluate dermoscopic findings in patients with CGDs and determine the dermoscopic criteria that could suggest the type of granulomatous disorder.

Material and methods

A total of 107 cases including 75 (70.09%) males and 32 (29.90%) females with an established diagnosis of cutaneous leishmaniasis (n = 49), cutaneous sarcoidosis (n = 23), granuloma annulare (GA) (n = 18), and tattoo granuloma (n = 17) confirmed by clinical and pathological studies were included. Based on the previous studies available in the literature, we wrote a checklist containing dermoscopic features of CGDs. Afterward, two dermatologists independently reviewed all dermoscopic images for the presence or absence of each item on the checklist. Descriptive analysis, fisher exact, chi‐square, and t‐test were used. The granulomatous disorders with larger sample sizes were selected for further analysis, including the univariate and conditional multivariate logistic regressions.

Results

The most prevalent nonvascular findings in all of our CGD patients were white scaling (N = 67%, 62.61%), diffuse or localized orange structureless areas (N = 53%, 49.53%), and diffuse erythema (N = 48%, 44.85%). Furthermore, the most frequent vascular findings in all of our CGD cases were branching and arborizing vessels (N = 30%, 28.03%), linear irregular (N = 30%, 28.03%), and dotted vessels (N = 27%, 25.23%).

Conclusion

For differentiating leishmaniasis from sarcoidosis by dermoscopy, white scaling and white scarring areas are more suggestive of cutaneous leishmaniasis, whereas the presence of arborizing vessels would be more in favor of sarcoidosis. When comparing GA to cutaneous leishmaniasis, the latter significantly shows more linear irregular vessels, hairpin vessels, white scaling, and white scarring areas. In the case of differentiating sarcoidosis from GA, the presence of hairpin vessels would be suggestive of sarcoidosis.

1. INTRODUCTION

Cutaneous granulomatous disorders (CGDs) are a group of skin diseases that share the common feature of granuloma formation. ¹ CGDs are usually categorized into infectious (such as leishmaniasis and lupus vulgaris) and noninfectious (such as granuloma annulare [GA] and necrobiosis lipoidica). ² Clinically, CGDs may have similar characteristics, and hence, distinguishing CGDs from one another and other dermatoses can be challenging. ³ , ⁴ , ⁵

Recent studies suggest that dermoscopy can be useful for the diagnosis of various dermatological conditions, namely, CGDs. ⁶ , ⁷ , ⁸ , ⁹ , ¹⁰ Granulomatous disorders can share some features, but an accurate assessment of various findings and their pattern can be useful in differentiating them. ¹¹ , ¹² , ¹³ In addition to common dermoscopic findings for CGDs, some peculiar dermoscopic characteristics can be helpful in distinguishing them. ¹⁴ , ¹⁵

The current study aimed to evaluate dermoscopic findings in patients with CGDs and determine the dermoscopic criteria that could suggest the type of granulomatous disorder in order to help dermatologists in their clinical diagnosis.

2. METHODS AND MATERIALS

The current study is a case‐series analysis conducted at a tertiary care hospital between the years 2017 and 2021. All cases with an established diagnosis of cutaneous leishmaniasis, GA, necrobiosis lipoidica, lupus vulgaris, cutaneous sarcoidosis, and tattoo granuloma confirmed by clinical and pathological studies were enrolled. All patients gave informed consent to take part in our study. Dermoscopic pictures were taken using FotoFinder medicam 1000 (FotoFinder Systems GmbH, Bad Birnbach, Germany). Based on the previous studies available in the literature, we wrote a checklist containing dermoscopic features of CGDs. ² The checklist is available in Supporting Information Files 1 and 2. Afterward, two dermatologists independently reviewed all dermoscopic images for the presence or absence of each item on the checklist. The results of the two experts’ checklists were rechecked by a third dermatologist for discrepancies. Data were analyzed using SPSS version 18. Descriptive analysis was conducted; the Fisher exact and chi‐square tests were used to compare qualitative data, and t‐test was used to compare quantitative data. The granulomatous disorders with larger sample sizes in our study were selected for further analysis. We used the univariate and conditional multivariate logistic regression analyses for cutaneous leishmaniasis, cutaneous sarcoidosis, and GA cases (the three conditions with larger sample sizes), and we included common dermoscopic variables, including vascular and nonvascular findings.

3. RESULTS

A total of 107 cases, including 75 (70.09%) males and 32 (29.90%) females, were enrolled (Tables 1, 2, 3). According to the results of our study, the most prevalent nonvascular findings in all of our CGD patients were white scaling (N = 67%, 62.61%) (p‐value = 0.001), diffuse or localized orange structureless areas (N = 53%, 49.53%) (p‐value = 0.001), and diffuse erythema (N = 48%, 44.85%) (p‐value = 0.001). Furthermore, the most frequent vascular findings in all of our CGD cases were branching and arborizing vessels (N = 30%, 28.03%) (p‐value = 0.001), linear irregular (N = 30%, 28.03%) (p‐value = 0.001), and dotted vessels (N = 27%, 25.23%) (p‐value = 0.018). All findings and patients’ characteristics are available in Tables 1, 2, 3.

TABLE 1.

Nonvascular dermoscopic findings

	Total (N = 107)	Cutaneous leishmaniasis (n = 49)	Cutaneous sarcoidosis (n = 23)	Granuloma annulare (n = 18)	Tattoo granuloma (n = 17)	p‐Value
White scaling	N = 67 (62.61%)	N = 43 (87.75%)	N = 10 (43.47%)	N = 3 (16.66%)	N = 11 (64.7%)	0.001
Diffuse erythema	N = 48 (44.85%)	N = 32 (65.3%)	0	N = 16 (88.88%)	0	0.001
White scarring area	N = 35 (32.71%)	N = 25 (51.02%)	0	0	N = 10 (58.82%)	0.001
Crust	N = 22 (20.56%)	N = 22 (44.89%)	0	0	0	0.001
Yellow scaling	N = 20 (18.69%)	N = 15 (30.61%)	N = 5 (21.73%)	0	0	0.003
Yellowish hue	N = 14 (13.01%)	N = 14 (28.57%)	0	0	0	0.001
Central ulceration	N = 12 (11.21%)	N = 12 (24.48%)	0	0	0	0.001
Whitish follicular plug	N = 17 (15.88%)	N = 10 (20.4%)	N = 7 (30.43%)	0	0	0.012
White starburst like pattern	N = 8 (7.47%)	N = 8 (16.32%)	0	0	0	0.017
Orange areas	N = 53 (49.53%)	N = 16 (32.65%)	N = 23 (100%)	0	N = 14 (82.35%)	0.001
Pustules	N = 6 (5.60%)	N = 6 (12.24%)	0	0	0	0.057
Yellowish follicular plug	N = 5 (4.67%)	N = 5 (10.2%)	0	0	0	0.102
Rosette like structure	N = 5 (4.67%)	N = 4 (8.16%)	0	N = 1 (5.55%)	0	0.343
Yellow structureless area	N = 36 (33.64%)	N = 6 (12.24%)	0	N = 14 (77.77%)	N = 16 (94.11%)	0.001
Central erosion	N = 1 (0.93%)	N = 1 (2.04%)	0	0	0	0.754
Globular whitish area	N = 4 (3.73%)	0	0	N = 4 (22.22%)	0	0.001
Tear‐drop shaped follicular plug	N = 0	(0)0	0	0	0	N/A
Milia‐like cysts	N = 0	(0)0	0	0	0	N/A
Whitish structure less area	N = 23 (21.49%)	0	N = 13 (56.52%)	N = 10 (55.55%)	0	0.001
Pigmentation structures	N = 7 (6.54%)	0	N = 5 (21.73%)	N = 2 (11.11%)	0	0.003
White reticulated lines	N = 3 (2.80%)	0	N = 3 (13.04%)	0	0	0.010
Perifollicular scale	N = 2 (1.86%)	0	N = 2 (8.69%)	0	0	0.059
Hair cast	N = 2 (1.86%)	0	N = 2 (8.69%)	0	0	0.059
Decreased follicular orifices	N = 1 (0.93%)	0	N = 1 (4.34%)	0	0	0.297
Dilated follicle	N = 1 (0.93%)	0	N = 1 (4.34%)	0	0	0.297
Crystalline structures	N = 0	0	0	0	0	N/A
Brownish structures	N = 13 (12.14%)	0	0	0	N = 13 (76.47%)	0.001
Crystalline structures and bluish area (tattoo ink)	N = 11 (10.28%)	0	0	0	N = 11 (64.7%)	0.001
Brown circles	N = 9 (8.41%)	0	0	0	N = 9 (52.94%)	0.001

TABLE 2.

Vascular dermoscopic findings

	Total (N = 107)	Cutaneous leishmaniasis (n = 49)	Cutaneous sarcoidosis (n = 23)	Granuloma annulare (n = 18)	Tattoo granuloma (n = 17)	p‐Value
Linear irregular	N = 30 (28.03%)	N = 20 (40.81%)	N = 7 (30.43%)	N = 1 (5.55%)	N = 2 (11.76%)	0.001
Glomerular vessels	N = 19 (17.75%)	N = 16 (32.65%)	N = 3 (13.04%)	0	0	0.001
Dotted vessels	N = 27 (25.23%)	N = 16 (32.65%)	N = 4 (17.39%)	N = 7 (38.88%)	0	0.018
Hairpin vessels	N = 18 (16.82%)	N = 13 (26.53%)	N = 5 (21.73%)	0	0	0.012
Polymorphic vessels	N = 11 (10.28%)	N = 11 (22.44%)	0	0	0	0.002
Branching vessels	N = 30 (28.03%)	N = 5 (10.20%)	N = 11 (47.82%)	N = 5 (27.77%)	N = 9 (52.94%)	0.001
Thrombotic vessels	N = 5 (4.67%)	N = 5 (10.20%)	0	0	0	0.092
Corkscrew vessels	N = 4 (3.73%)	N = 4 (8.16%)	0	0	0	0.164
Comma vessels	N = 1 (0.93%)	N = 1 (2.04%)	0	0	0	0.743
Red lacuna	N = 1 (0.93%)	N = 1 (2.04%)	0	0	0	0.743
Vessels surrounded by whitish halo	N = 1 (0.93%)	N = 1 (2.04%)	0	0	0	0.743
Strawberry‐like vessels	N = 0	0	0	0	0	N/A
Linear vessels	N = 2 (1.86%)	0	N = 2 (8.69%)	0	0	0.070
Network vessels	N = 1 (0.93%)	0	0	N = 1 (5.55%)	0	0.172
Well‐focused vessels	N = 0	0	0	0	0	N/A
Branching serpentine vessels	N = 0	0	0	0	0	N/A

TABLE 3.

Characteristics of patients

		Cutaneous leishmaniasis (n = 49)	Cutaneous sarcoidosis (n = 23)	Granuloma annulare (n = 18)	Tattoo granuloma (n = 17)
Gender	Male	39 (79.59%)	13 (56.52%)	6 (33.33%)	17 (100%)
	Female	10 (20.40%)	10 (43.47%)	12 (66.66%)	0
Mean age		46.36 ± 7.66	43.6 ± 11	46.7 ± 22	42.5 ± 11
Most common locations	Face and neck	20 (40.81%)	11 (47.82%)	3 (16.66%)	17 (100%)
	Lower extremities	18 (36.73%)	None	2 (11.11%)	None
	Upper extremities	11 (22.44%)	4 (17.39%)	12 (66.66%)	None
	Trunk	None	8 (34.78%)	1 (5.55%)	None

Of note, there were only three cases of necrobiosis lipoidica and one case of lupus vulgaris, and due to the low number of cases, they were not included in our further statistical analysis.

The most common vascular and nonvascular findings in leishmaniasis were linear irregular vessels (N = 20%, 40.81%) and white scaling (N = 43%, 87.75%), respectively. Regarding the patients diagnosed with cutaneous sarcoidosis, the most prevalent vascular finding was branching vessels (N = 11%, 47.82%), and the most frequent nonvascular finding was orange areas (N = 23%, 100%). In patients diagnosed with GA, the most common vascular finding was dotted vessels (N = 7%, 38.88%), and the most prevalent nonvascular finding was diffuse erythema (N = 16%, 88.88%). Moreover, in tattoo granuloma patients, branching vessels (N = 9%, 52.94%) and yellow structureless areas (N = 16%, 94.11%) were the most frequently observed vascular and nonvascular findings.

The univariate analysis performed on the three most common granulomatous conditions (cutaneous leishmaniasis, cutaneous sarcoidosis, and GA) revealed several dermoscopic predictors. Based on these results, the main positive dermoscopic predictors of cutaneous leishmaniasis versus cutaneous sarcoidosis were white scaling (p‐value = 0.0001) and white scarring areas (p‐value = 0.0001), and the negative predictor is branching and arborizing vessels (p‐value = 0.001). Positive predictors of cutaneous leishmaniasis versus GA were linear irregular vessels (p‐value = 0.02), hairpin vessels (p‐value = 0.0001), white scaling (p‐value = 0.0001), and white scarring areas (p‐value = 0.0001). To distinguish cutaneous sarcoidosis from GA, the positive predictor was hairpin vessels (p‐value = 0.0001). The multivariate logistic regression analysis for cutaneous leishmaniasis versus cutaneous sarcoidosis showed that the white scaling (p‐value = 0.01) and white scarring (p‐value = 0.001) were more associated with cutaneous leishmaniasis, and branching and arborizing vessels (p‐value = 0.02) were more associated with cutaneous sarcoidosis. Hairpin vessels (p‐value = 0.0001) and white scaling (p‐value = 0.007) were associated with cutaneous leishmaniasis versus GA (Table 4).

TABLE 4.

Results of univariate and multivariate analyses. A p‐value less than 0.05 was considered significant

	Univariate			Multivariate
	p‐Value	OR	95% CI	p‐Value	OR	95% CI
Linear irregular vessels
CL vs. CS	0.39	1.57	0.59–4.52	–
CL vs. GA	0.02	11.72	1.44–95.33	–
GA vs. CS	0.07	0.13	0.01–1.21	–
Dotted vessels
CL vs. CS	0.18	2.3	0.67–7.89	–
CL vs. GA	0.63	0.76	0.24–2.33	–
GA vs. CS	0.1	3.02	0.71–12.7	–
Hairpin vessels
CL vs. CS	0.66	1.3	0.4–4.21	–
CL vs. GA	0.0001	10.5	8.5–85.35	0.0001	2.92	0.13–6.35
GA vs. CS	0.0001	2.58	6.13–6.44	–
Branching and arborizing vessels
CL vs. CS	0.001	0.12	0.03–0.42	0.02	0.11	0.01–0.78
CL vs. GA	0.08	0.29	0.07–1.18	–
GA vs. CS	0.19	0.42	0.11–1.56	–
White scaling
CL vs. CS	0.0001	9.31	2.84–30.53	0.01	18.95	1.93–186.16
CL vs. GA	0.0001	35.83	7.95–161.46	0.007	27.86	2.48–312.62
GA vs. CS	0.07	0.26	0.05–1.15	–
White scarring area
CL vs. CS	0.0001	20.5	3.55–50.33	0.001	5.55	2.13–10.5
CL vs. GA	0.0001	15.55	9.25–110.51	–
GA vs. CS	0.43	3.38	0.84–13.52	–

Abbreviations: CL, cutaneous leishmaniasis; CS, cutaneous sarcoidosis; GA, granuloma annulare.

4. DISCUSSION

Based on the results of our study, the multivariate analysis showed that white scaling, white scarring areas, and hairpin vessels are more likely to be indicative of cutaneous leishmaniasis (Figure 1). Moreover, branching and arborizing vessels are more in favor of cutaneous sarcoidosis. Apart from the yellow–orange structures that are the hallmark of granulomatous diseases, our study revealed that cutaneous leishmaniasis mainly presents with white scaling, diffuse erythema, linear irregular, glomerular, and dotted vessels, and cutaneous sarcoidosis can be diagnosed with whitish structureless areas, branching, linear irregular, and hairpin vessels. We observed diffuse erythema, white structureless area, and dotted and branching vessels as the most frequent dermoscopic findings for GA (Figure 2). Regarding tattoo granuloma, we observed brownish‐gray structureless areas as well as white scale, crystalline structures, and bluish areas (tattoo ink) in addition to branching and linear irregular vessels (Figure 3).

FIGURE 1.

(A) Dermoscopic findings in a patient with cutaneous leishmaniasis, including orange structureless area, white scarring area, central keratinous plaque, and white scale. Vascular findings include hairpin vessels, glomerular vessels, and linear irregular and dotted vessels; (B) leishmaniasis on the face of a young man with orange structureless area, white scarring areas, white scale, and arborizing vessels

FIGURE 2.

Dermoscopy of a patient with granuloma annulare including pinkish to orange area. Vascular findings are dotted vessels.

FIGURE 3.

Dermoscopy of a patient with tattoo granuloma. Orange areas, brown pigmentations are present and crystalline structure are seen.

A characteristic dermoscopic feature of all CGDs is the presence of structureless orangish or yellowish‐orange areas, either dispersed in a focal or diffuse pattern. ² This finding indicates the presence of dense and compact granulomatous infiltrate in the dermis, and it is better visible by applying slight pressure (as a result of erythema reduction). Of note, none of these findings are specific to CGDs, and they can be observed in other dermatoses. The absence of such areas does not rule out the diagnosis of CGDs because they may be difficult to see in the early stages. Other common dermoscopic findings of CGDs include vessels (usually indicating early or active phase) and whitish areas (often in long‐lasting lesions). ⁸

According to Errichetti et al.’s study (2018), in dermoscopy, cutaneous sarcoidosis, cutaneous leishmaniasis, and lupus vulgaris show diffuse or localized, structureless, orange yellowish areas (usually called “grains of sand” in lupus vulgaris and teardrop‐like areas in leishmaniasis) as well as focused linear or branching vessels, which is consistent with the results of our study (Tables 1 and 2) (Figure 4). ² , ⁹ In this regard, in accordance with the findings of our study, Pellicano et al. concluded that the presence of small grouped, translucent orange globular structures and linear vessels with variable sizes are highly suggestive of cutaneous sarcoidosis. ¹⁶ Furthermore, in another study by Chauhan et al. on a patient with cutaneous sarcoidosis, multiple linear and branching vessels over translucent yellowish‐orange globular structures as well as scar‐like depigmented areas were detected. ¹⁵

FIGURE 4.

Sarcoidosis on the forehead of a man with orange structureless areas, diffuse erythema, white structureless areas, white scales, hairpin vessels at the periphery, and arborizing and corkscrew vessels in the center.

The most frequent dermoscopic findings of cutaneous leishmaniasis are diffuse erythema and polymorphic vessels. Cutaneous leishmaniasis is also reported to display hyperkeratosis, further features of vascularity (hairpin, comma‐shaped, glomerular‐like, or corkscrew vessels), central ulcerations, and white peripheral projections (white starburst pattern). Yucel et al. concluded that yellow tears, white starburst‐like patterns, and salmon‐colored ovoid structures are likely to appear specifically in these patients. In addition, irregular linear and treelike pattern vascular findings were noted in these patients. ¹³ In another study, generalized erythema, yellow tears, and starburst‐like patterns in addition to linear irregular, hairpin, comma‐shaped, and arborizing vessels were mostly observed, which is in accordance with our findings. ¹⁴ The most common dermoscopic findings in our study are white scaling, diffuse erythema, linear irregular, glomerular, and dotted vessels and are in accordance with previous studies. ¹ , ²

The main dermoscopic hallmark for GA is the presence of unfocused vessels having a variable morphology (dotted, linear irregular, and/or branching in respect of frequency) with a pinkish–reddish background as well as yellowish‐orange, and whitish areas. ⁵ , ⁶ , ⁷ , ⁸ , ⁹ In a study done by Errichetti et al., it was observed that blurry vessels (dotted, linear irregular, and branching) on a pinkish–reddish background, followed by whitish and/or yellow‐orangish areas, are the most common dermoscopic findings in these patients. ¹¹ Moreover, the results of a study done by Pellicano et al. show that all cases of GA were dermoscopically recognized by peripheral, structureless orange‐reddish borders. ¹² In this vein, we found diffuse erythema, yellow, and white structureless area, and dotted and branching vessels as the most prevalent dermoscopic findings for GA. When comparing GA to cutaneous leishmaniasis patients, our study indicates that cutaneous leishmaniasis cases significantly showed more linear irregular vessels (p‐value = 0.02), hairpin vessels (p‐value = 0.0001), white scaling (p‐value = 0.0001), and white scarring (p‐value = 0.0001) areas. To differentiate cutaneous sarcoidosis from GA, the positive predictor of dermoscopy was hairpin vessels (p‐value = 0.0001) meaning hairpin vessels are more common in sarcoidosis.

Previous studies have reported the presence of crystalline structures, and bluish spots corresponding to the cosmetic tattoo in the dermoscopic evaluation of tattoo granuloma. ² In this study, we observed yellowish, orange, and brownish‐gray structure‐less areas in our patients. Moreover, white scale, crystalline structures, bluish area (tattoo ink), branching, and linear irregular vessels were among the most prevalent dermoscopic findings.

Some of the limitations of our study included the retrospective design of the study and the small sample size. Furthermore, the absence of dermoscopic and histopathological correlation evaluation can be considered another limitation. For the future, we recommend a prospective larger study correlating the clinical, histopathological, and dermoscopic features in order to determine the distinguishing dermoscopic criteria.

5. CONCLUSION

Our study suggests that dermoscopy is a valuable noninvasive tool in the diagnosis of CGDs. The presence of orangish‐yellow structureless areas and linear or branching vessels in dermoscopy should raise suspicion of CGDs. However, in order to reach a definite diagnosis, dermoscopic results should be accompanied by a thorough clinical examination, the patient's history, and histopathological findings.

Based on the results of our study, for differentiating leishmaniasis from sarcoidosis by dermoscopy, white scaling and white scarring area are more suggestive of cutaneous leishmaniasis, whereas the presence of arborizing vessels would be more in favor of sarcoidosis. When comparing GA to cutaneous leishmaniasis, the latter significantly shows more linear irregular vessels, hairpin vessels, white scaling, and white scarring areas. In the case of differentiating sarcoidosis from GA, the presence of hairpin vessels would be suggestive of sarcoidosis.

CONFLICT OF INTEREST

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Supporting information

Supporting Information File 1 Checklist for nonvascular dermoscopic findings

Supporting Information File 2 Checklist for vascular dermoscopic findings.

Kalantari Y, Peymanfar AA, Mahmoudi H, Daneshpazhooh M, Etesami I. Dermoscopy of cutaneous granulomatous disorders: A study of 107 cases. Skin Res Technol. 2023;29:e13273. 10.1111/srt.13273

DATA AVAILABILITY STATEMENT

Research data are not shared.