br Materials and methods br Results br Discussion LP
Materials and methods
Discussion LP is a relatively common chronic inflammatory disease of the skin, mucous membranes, and hair follicles. The clinical characteristics of LP include lesions with fine white-grayish crossing lines and streaks, referred to as WS. Hyperparakeratinization and hyperorthokeratinization are common findings and may clinically coincide with WS. The performance of dermoscopy has been investigated by many authors. According to evidence-based studies and meta-analysis, its use increases the diagnostic accuracy between 5% and 30% over clinical visual inspection. Dermoscopy is widely used in the diagnosis of pigmented and nonpigmented skin tumors. However, unlike other skin tumors, there are limited data about the dermoscopic pattern of inflammatory skin disorders, such as LP, plaque psoriasis, pityriasis rosea, and dermatitis. Although the dermoscopic features of common inflammatory dermatoses have not been well studied, several studies have characterized the typical dermoscopic features of LP. In one of those studies, WS were the most constant finding associated with LP (92%; p < 0.001). In another study that compared dermoscopic features of psoriasis, dermatitis, LP, and pityriasis rosea, the white-grayish crossing lines of WS were exclusively detected in LP (96%; p < 0.001). In dermoscopy, findings of WS correspond with compact orthokeratosis above the zones of wedge-shaped hypergranulosis (centered around acrosyringia and acrotrichia) histopathologically. Peripheral linear freedom perpendicularly surrounding the border of a lesion (radial capillaries) are usually intermingled with the WS border projections. WS has been observed to disappear after treatment, suggesting that dermatologists can use it as an activation marker in LP lesions. Conversely, vascular patterns have been shown to occur at a higher rate in AGLP, which may be attributable to the rapid onset of the lesions. However, in our study, the patients who were classified as having AGLP (Patients 2 and 3) had no vascular patterns, dermoscopically. The histologic correlate of WS seems to be a compact orthokeratosis above the zones of wedge-shaped hypergranulosis. Conversely, in the pigmented type of LP the epidermis is thinner than other types of LP, and there are less granular wedge-shaped structures. For this histopathological reason, it is difficult to detect WS in the pigmented type of LP. The WS is less likely to correspond to the regression and activation phases of the disease. Finally, we must take into account that the clinical profitability of dermoscopy of inflammatory dermatoses must include not only a diagnostic purpose but also other fundamental aspects of daily practice, such as the improvement of morphological knowledge. Vázquez-López et al introduced several hyperpigmented forms of LP. In their study, the hyperpigmented lesions of 10 patients, which were biopsy-proven LP, were estimated by three distinct patterns: (1) diffuse (lesions showing diffuse, structureless, brownish areas); (2) dotted (lesions demonstrating fine or coarse gray-blue or brown dots or globules); and (3) mixed (diffuse brownish areas with dotted structures). According to the findings of that study, if the lesion has more diffuse hyperpigmented patterns, the lesion may resolve more quickly. According to this pilot study, dermoscopy may be useful for determining the prognosis of LP patients. In a recent study, among 170 classical LP lesions from 60 patients, WS were observed in 152 lesions (89.4%). In addition, different WS, pigment, and vascular patterns were also seen and were collectively referred to as an “LP variant.” In that study, pigment patterns corresponded to dermal melanophages and pigment incontinence. The authors commented that the variable dermoscopic patterns show the dynamic course of the LP disease. Interestingly, subspecies also assumed that WS can be used as an activation marker in LP lesions because WS disappeared after treatment in some cases. However, in our study only two patients were in a regression phase, and the remaining five patients were in an active phase of the disease. Even in the active phase, WS patterns were not observed. However, in other studies, in the early phase of the disease a peppering pigment pattern is seen that progresses to a reticular pattern over time. Conversely, in our study the two patients (Patients 5 and 6) who showed an LP in the regression phase did not have a reticular pattern. We can assume that the patterns of pigmentation do not correspond to the activation status of the disease. Few studies have reported variant dermoscopic findings of LP. This study was intended to emphasize the role of dermoscopy, which can help to identify the clinical status of LP and its correlation to the results of histopathologic examinations.