Pityriasis lichenoides et varioliformis acuta in skin of color: new observations by dermoscopy

Background Pityriasis lichenoides is an uncommon skin disease that presents in three different forms: pityriasis lichenoides et varioliformis acuta (PLEVA), pityriasis lichenoides chronica (PLC) and febrile ulceronecrotic-Mucha-Habermann disease. These represent a spectrum of a disease. PLEVA presents as skin eruption of multiple, small, red papules that develop into polymorphic lesions with periods of varying remissions, as well as possible sequels of hyper/hypopigmentation and varicella-like scars. Diagnosis of this condition is mainly clinical, and sometimes clinical differentiation from other conditions may be a difficult task that often requires histological analysis. In this study, PLEVA lesions were examined by dermoscopy, and the significance of specific dermoscopic findings was investigated in order to facilitate their differentiation from other inflammatory conditions. Objectives To evaluate dermoscopic patterns in PLEVA and to correlate these patterns with histopathology. Materials and methods The study was conducted at S. Nijalingappa Medical College, Bagalkot. It was an observational case series study and patients were selected randomly. Ethical clearance and informed consent were obtained. PLEVA lesions in early and late phases were evaluated. A manual DermLite 3 (3Gen, San Juan Capistrano, CA) dermoscope attached to a Sony (Cyber Shot DSC-W800, Sony Electronics Inc., San Diego, California, USA, digital, 14 mega pixels) camera was employed. Histopathology was done to confirm the diagnosis. Data was collected and analyzed. Results were statistically described in terms of frequencies and types of dermoscopic patterns. Results There was a total of 14 patients; 8 males and 6 females. Mean age of patients was 19 years. Mean duration of disease was 7 months. Dermoscopy in early-phase lesions revealed amorphous brownish areas around the hair follicles, dotted vessels, and scaling. Dermoscopy in late-phase lesions showed whitish-structureless areas and central white crust within whitish-structureless rim with scale, focal bluish-grayish areas or centrifugal strands irregularly distributed along the periphery and yellow structures. Red dots and hemorrhage were seen at the center and glomerular vessels at the periphery. Conclusion PLEVA demonstrates specific dermoscopic patterns that correlate well with histologic changes. New dermoscopic findings are described. Thus, dermoscopy is a good diagnostic tool in the clinical diagnosis of PLEVA.

Dermoscopy is a non-invasive technique that allows a rapid and magnified in vivo observation of the skin surface. Dermoscopy is mainly utilized for the evaluation of pigmented skin lesions and has increasing applications in dermatology [3]. Here, authors evaluated dermoscopic patterns in PLEVA in brown skin, and these patterns may assist the clinical diagnosis.

Objectives
To evaluate dermoscopic patterns in PLEVA and to correlate these patterns with histopathology. and disease duration were documented. Lesions with less than 2 months' and more than 2 months' duration were arbitrarily termed as early and late lesions. These were referred to as target lesions and were selected for dermoscopic examination. Skin biopsies were taken from target lesions to confirm the diagnosis. Same dermatologist evaluated dermoscopic patterns and was unaware of clinical diagnosis. The pathologist was also unaware of the diagnosis and same pathologist evaluated histopathological changes. Data was collected and analyzed. The results were statistically described as types of dermoscopic patterns.

DERMOSCOPIC EXAMINATION
A DermLite 3 dermoscope (10x magnification) with both polarized and non-polarized lights was employed in the study.
A Sony camera was attached to save the images. Initially,  Table 1, and corresponding histopathological changes are depicted in Table 2.     Dermoscopy is a novel diagnostic technique; beside its traditional use in melanoma detection, it is being used more and more in the assessment of other general dermatologic conditions, namely scalp and hair disorders (trichoscopy), nails abnormalities (onychoscopy), skin infections and infestations (entomodermoscopy), and cutaneous inflammatory diseases (inflammoscopy) [3]. In this study, authors evaluated dermoscopic patterns in PLEVA.
In this study, dermoscopy of early PLEVA lesions i.e., lesions aged less than 2 months revealed an amorphous brownish area around the hair follicles within a rim of white scale and dotted vessels at the periphery. In a study of dermoscopy of PLEVA by Lacarrubba et al, the authors observed an amorphous brownish structure and a ring of pinpoint and linear vessels in a "targetoid" pattern surrounding whitish-structureless areas [8]. Similar findings were observed in this study. However, the targetoid pattern of vessels was not observed. Vessels were in dotted pattern at the periphery. These correspond to microhemorrhages and extravasations of red blood cells in the papillary dermis. This disparity may be the result of the early stage of lesions and the dermoscopic technique followed in this study. Interestingly, an amorphous brownish structure was noted around the hair follicle. This finding was not mentioned in the previous study.    it takes on the "starburst" pattern [12], and in eccrine spiradenoma, it is arranged as structureless areas surrounding serpentine vessels [13].  Late-phase lesions demonstrated whitish-structureless areas and a central crust-plug surrounded by whitish rim with scale. This is in correlation with previous observation [8]. Red dots and hemorrahges were observed in the center, within the whitish rim. Whitish-structureless areas are seen in inflammatory conditions such as prurigo nodularis, hypertrophic lichen planus, and morphea and in some of the non-melanocytic skin tumors [9][10][11][12][13]. In hypertrophic lichen planus and prurigo nodularis it is referred to as pearly white structure spread over the entire lesion and seen characteristically in a "starburst" pattern in prurigo nodularis; and in hypertrophic lichen planus it is distributed diffusely in the centre [9,10]. In morphea, it appears as whitish strands with dilated blood vessels [11]. In non-melanocytic tumors, white structures are arranged in a specific pattern, which give a      structureless areas correspond to hemosiderin deposition in the dermis [16]. In this study, the orange hue was absent and only the yellowish color was appreciated. Hence, the authors propose that yellow structures in PLEVA are produced as a result of the increased duration of lesions and that they represent spongiosis and basal cell degeneration on histology. Yellow structures noted in hypertrophic lichen planus correspond to spongiosis and basal cell degeneration [10,15]. In hypertrophic lichen planus, yellow structures are arranged in a "lacy network" pattern [10] and in dermatitis, they are in a diffuse pattern, giving rise to the "yellow clod" sign [17]. of dermatitis [17]. In seborrheic keratosis and clear cell carcinoma, vessels are in "hair-pin" and "string of pearls" patterns respectively [18]. In pityriasis lichenoides chronica, milky red areas/globules, linear irregular and branching vessels are seen [16]. Hence, the pattern of blood vessels is of diagnostic importance in the dermoscopic studies.

Discussion
In the present study, the authors noted focal bluishgrayish areas and yellow structures, which are not described

Conclusion
PLEVA is a rare disorder that can be challenging to differentiate clinically from a number of common dermatoses, and