Dermatology: Practical and Conceptual Observation | Dermatol Pract Concept 2015;5(4):13 51 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Introduction Dermoscopy is a non-invasive tool that allows us to recognize key structures of lichen planus, which is useful for its diagno- sis, follow-up and prognosis. Case reports Case 1 A 50-year-old female patient with no relevant history was seen in the hospital due to a pruritic erythematous papule with months of evolution on the anterior side of her right lower limb associated with asymptomatic confluent whitish papules on buccal mucosa. Two weeks later it had evolved with an eruption of pruritic violaceous plaques in the neck area. Dermoscopy of the lesion on the patient’s thigh revealed small pinpoint vessels associated with whitish striations (projections) with a “fern leaf’ aspect on an erythematosus background (Figure 1). Pathological examination revealed: sawtooth acanthosis, orthokeratotic hyperkeratosis, hypergranulosis, hydropic degeneration of the basal layer, and band-like lymphocytic infiltrate compatible with lichen planus. Case 2 A 36-year-old female patient, with no medical history, sought medical attention due to multiple alopecic areas on the scalp of uneven distribution, erythema and follicular plugging. A trichoscopy revealed multiple irregular cicatricial alo- pecic areas with perifollicular whitish-gray scaling associated Dermoscopic findings in different clinical variants of lichen planus. Is dermoscopy useful? Paula Friedman1, Emilia Cohen Sabban2, Carolina Marcucci3, Rosario Peralta3, Horacio Cabo2 1 Department of Dermatology, Instituto de Investigaciones Médicas “A. Lanari”, University of Buenos Aires, Argentina 2 Dermatology, Buenos Aires, Argentina Key words: lichen planus, dermoscopy Citation: Friedman P, Cohen Sabban E, Marcucci C, Peralta R, Cabo H. Dermoscopic findings in different clinical variants of lichen planus. Is dermoscopy useful? Dermatol Pract Concept 2015;5(4):13. doi: 10.5826/dpc.0504a13 Received: May 21, 2015; Accepted: September 17, 2015; Published: October 31, 2015 Copyright: ©2015 Friedman 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. All authors have contributed significantly to this publication. Corresponding author: Paula Friedman, MD, 2562 Arcos St, 2nd floor, Buenos Aires, Argentina. Tel. +0541158406476. Email: paufriedman@gmail.com Lichen planus (LP) is a papulosquamous dermatosis that involves the skin, scalp, nails and mucous membranes. Although its pathogenesis is still unknown, there is evidence that an imbalance of immu- nologic cellular reactivity plays an important role. Histopathologic examination reveals characteristic interface dermatitis. Dermoscopy is a non-invasive tool, useful in the assessment of inflammatory dermatoses, such as lichen planus. In this paper we describe the dermoscopic findings of different variants of LP (ungual, cutaneous, planopilaris, pigmentosus). ABSTRACT 52 Observation | Dermatol Pract Concept 2015;5(4):13 Mycological exam, X-ray of both hands, routine laboratory tests and HBV, HCV and HIV serologies were unremarkable. Pathological examination of the nail bed and plate (Pro- tocol 133239, Dr. Casas) revealed: hyperkeratosis, para- with erythema, arboriform vessels, absence of follicular open- ings, and follicular plugging (Figures 2, 3). Pathological examination (Protocol 14-03006, Dr. Calb) revealed: hair follicles with vacuolar degeneration of follicular wall basal cells and numerous perifollicular lymphocytes; the histological image was compatible with lichen planopilaris. Case 3 A 59-year-old male patient with no medical history was seen in the hospital due to an active and progressive onychodys- trophy of the first, fourth and fifth fingers of both hands, and the third finger of the left hand, of 1 year’s evolution. Within the nail, there was pterygium, thinning, and destruction of the nail plate, longitudinal ridging, fissuring, onycholysis and subungual hyperkeratosis. The rest of the physical examina- tion was unremarkable (Figure 4). On dermoscopy, we observed chromonychia, subungual hyperkeratosis, onycholysis, and destruction of the nail plate (Figure 5). Figure 1. Leaf venation pattern. White pearly structures correspond- ing to WS with arboriform projections of “fern leaf” aspect (arrow), erythematous globules at their edges (circle). [Copyright: ©2015 Friedman et al.] Figure 2. Absence of follicular openings (circle), erythema, perifol- licular scales (arrow). [Copyright: ©2015 Friedman et al.] Figure 3. Absence of follicular openings (circle), whitish-gray scales (arrow), arboriform vessels (star). [Copyright: ©2015 Friedman et al.] Figure 4. (a & c) Destruction of nail plate; (b) fissuring, thinning, fragility, longitudinal ridging; (d) chromonychia, trachyonychia. [Copyright: ©2015 Friedman et al.] Figure 5. (a) Destruction of nail plate; (b) onycholysis; (c) subungual hyperkeratosis; (d) chromonychia. [Copyright: ©2015 Friedman et al.] Observation | Dermatol Pract Concept 2015;5(4):13 53 Discussion Cutaneous lichen planus The classic skin lesion consists of a flat-topped polygonal papule that is slightly erythematous to violaceous. A thin and adherent scale can be observed on top of it. On the surface there are reticular or pinpoint whitish structures, known as Wickham striae (WS), pathognomonic of this entity [1]. Dermoscopy findings consist of polymorphic pearly whit- ish structures that correspond to WS with arboriform “fern leaf” projections. At the borders linear vessels (radial capillar- ies) and erythematous globules may be observed (Figure 1), WS dermoscopic patterns [2] (Table I): • Reticular (the most common) • Circular • Radial streaming • Leaf venation: characterized by delicate secondary striae branching from the centered WS venation, linked together at either end, mimicking the crystal structure of snow • Starry sky/white dots: clustered, follicular white dots At dermoscopy, the WS is the diagnostic key to differen- tiate lichen planus from other entities such as the pityriasis rosea and psoriasis [3,4,5]. Lichen planopilaris Lichen planopilaris (LPP) is characterized by keratotic fol- licular papules that coalesce, forming plaques. At the final stage, the scalp shows multiple cicatricial alopecic areas with irregular aspect, perifollicular erythema and absence of fol- licular openings with follicular plugging [6]. Trichoscopy reveals multiple irregular cicatricial alopecic areas with perifollicular whitish-gray scaling associated with erythema, arboriform vessels, absence of follicular openings and follicular plugging (Figures 2, 3). Dermoscopic findings vary according to the stage of evolution and the degree of disease activity. In early stages, perifollicular inflammation leads to the appearance of whit- ish-gray scales (peripilar casts) associated with perifollicular erythema, characterized by the presence of arboriform ves- keratosis, focal hypergranulosis, and inflammatory activity, consisting of band-like lymphocyte infiltration that involved the epithelial connective interface, compatible with lichen planus of the nail bed. Case 4 A 59-year-old female patient with no medical history sought medical attention since she had bilateral brownish-violet macules localized to her armpits and groin that had evolved over years. They exhibited a lighter center, had well-defined limits, and were 0.5 to 1 cm in diameter. They were slightly itchy. There was no nail or mucous involvement. The dermoscopy image revealed a mixed pattern, char- acterized by brownish-gray dots with diffuse brownish areas (Figure 6). Pathological examination (Protocol 14-06238, Dr. Calb) revealed hyperkeratosis, hypergranulosis, acanthosis, inter- papillary ridges of irregular outline, vacuolated basal cell with juxtaposed lymphocytes, colloid bodies in the epidermis. The superficial dermis revealed melanophages and band-like lymphocytic infiltrate compatible with lichen planus. Figure 6. Mixed pattern: blue, gray, brown dots (arrow). Brownish structureless areas (circle). [Copyright: ©2015 Friedman et al.] 54 Observation | Dermatol Pract Concept 2015;5(4):13 Nail lichen planus The clinical manifestations of nail lichen planus are thinning, fragility, and destruction of the plate nail, longitu- dinal ridging, fissuring, onycholysis, trachyonychia, chromonychia and sub- ungual hyperkeratosis [10] (Figure 4). Dermoscopy findings demonstrate the compromise of the matrix that leads to the thinning and consequent fragility of the nail plate with fissuring, pitting, and its progression to trachyonychia, longitudinal ridging, dorsal pterygium, erythematous patches in the lunula, erit- ronychia, melanonychia and atrophy. sels. In LPP, the inflammatory phenom- enon usually affects the hair follicles in a selective manner with respect to the interfollicular epidermis (this sign helps its differentiation from other causes of cicatricial alopecia, such as chronic dis- coid lupus) [7,8]. In the fibrotic stage, whitish or milky-red areas are observed, covered by “classic irregular whitish dots” (fibrous tracts as a result of a variable loss of follicular units). Additionally, there are blue-violet areas and blue-gray dots reflecting perifollicular incontinen- tia pigmenti [9] (Table II). The compromise in the nailbed would explain the subungual hyperkeratosis, chromonychia and the onycholysis [11] (Figure 5) (Table III). Lichen planus pigmentosus inversus Lichen planus pigmentosus inversus is an uncommon variant of lichen planus pigmentosus involving predominantly folds, characterized by the presence of well-defined, brownish-purple oval macules, whose size varies from few millimeters to several centimeters and which may adopt a linear configura- tion. The lesions tend to be bilateral and asymptomatic, although some patients report mild pruritus. They heal belat- edly, leaving an area of atrophic and hyperpigmented skin [12]. Dermoscopic patterns (Table IV): • Diffuse: characterized by diffuse, structureless, brownish areas prob- ably associated with epidermal pig- mentation • Dotted: fine or coarse gray-blue or brown dots or globules related to dermal melanophages • Mixed: combining diffuse brownish areas with dotted structures Dermoscopic findings are of prognos- tic value, since those lesions with a dotted pattern tend to be persistent because the pigment is localized deeper [13]. Conclusion We describe the key dermoscopic findings of lichen planus and the different clinical variants, highlighting that dermoscopy can improve the diagnosis and follow-up of patients with this dermatosis. References 1. Sharma A, Bialynicki-Birula R, Schwartz R. Lichen planus: An update and review. Cutis. 2012;90:17-23. 2. Tan C, Min ZS, Xue Y, Zhu WY. Spec- trum of dermoscopic patterns in lichen planus: a case series from China. J Cutan Med Surg. 2014:18(1):28-32. Observation | Dermatol Pract Concept 2015;5(4):13 55 9. Rudnicka L, Olszewska M, Rakowska A, Slowinska M. Trichos- copy update 2011. J Dermatol 2011;5(4):82-8. 10. Goettmann S, Zaraa I, Moulonguet I. Nail lichen planus: epide- miological, clinical, pathological, therapeutic and prognosis study of 67 cases. J Euro Acad Dermatol Venereol. 2012;26:1304-9. 11. Nakamura R, Broce AA, Palencia D, Ortiz NI, Leverone A. Der- matoscopy of nail lichen planus. Int J Dermatol. 2013;52:684-7. 12. Gomez B, Huerta Salazar CM, Lopez S, Romano S, Lorenz AM. Liquen plano pigmentado: a proposito de un caso y revisión de literatura. Arch Argent Dermatol. 2012; 62:102-5. 13. Vázquez-López F, Maldonado-Seral C, López-Escobar M, Pérez- Oliva N. Dermoscopy of pigmented lichen planus lesions. Clin and Exp Dermatol. 2003;28:554-5. 3. Vásquez-López F, Gómez-Diez S, Sánchez J. Dermoscopy of active lichen planus. Arch Dermatol. 2007;143(8):1092. 4. Zalaudek I, Argenziano G. Dermoscopy subpatterns of inflamma- tory skin disorders. Arch Dermatol. 2006;142(6):808. 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 Dermatol. 2012;166(6):1198-205. 6. Tosti, A. Lichen planopilaris. In: Tosti A (ed.) Dermoscopy of Hair and Scalp Disorders with Clinical and Pathological Correlations. London: Informa Healthcare, 2007:98-104. 7. Sánchez Dueñas L. Dermatoscopía en enfermedades del pelo y la piel cabelluda. Dermatol Rev Mex. 2012;56(3):187-92. 8. Tosti A, Duque-Estrada B. Dermoscopy in hair disorders. J Egypt Women Dermatol Soc. 2010;7:1-4.