Dermoscopic Features of Plaque Psoriasis and Lichen Planus: New Observations

Abstract

Background: Dermoscopic features of common inflammatory dermatoses are not well studied and previous reports on this topic are limited to the search of vascular features (capillaroscopy). Objective: Dermoscopic features of psoriasis and lichen planus (LP) are investigated to determine both vascular and nonvascular features of these two dermatoses. Patients and Methods: Dermoscopic images of 25 patients with LP and 20 patients with plaque psoriasis (PP) were evaluated. Findings were statistically analyzed including the reproducibility of scoring (Cohen’s kappa statistics). Results: Our observations clearly showed that the evaluation of both vascular and nonvascular findings improved the surface microscopy of these diseases. A vascular feature (homogeneous red globules) was the most significant dermoscopic finding in the PP dermoscopic pattern (20/20, 100%; p < 0.001). A nonvascular feature (whitish striae) was the most significant dermoscopic feature in the LP pattern (23/25, 92%; p < 0.001). Dermoscopic features of LP also included gray-blue dots, comedo, milium-like cysts, and vascular structures (red lines). The intraobserver and interobserver reproducibility of scoring was very high (k value, 0.9). Conclusion: Our study shows for the first time that the efficacy of surface microscopy of common inflammatory dermatoses may be improved by investigating both vascular and nonvascular findings and its practicability in daily practice by using the dermoscope. Although dermoscopy does not provide clear additional help in the clinical differentiation between typical PP and LP, it could be helpful in patients with darker skin and for teaching settings.

Dermoscopy in clinically atypical psoriasis

“…1,2 Diagnosis of psoriasis is usually established clinically, based on the characteristic morphology and distribution of lesions. However, cases of psoriasis with atypical presentation do exist.…”

Dermoscopic findings in psoriasis and seborrheic dermatitis on the scalp and correlation with disease severity

“…Dermoscopic evaluations of psoriasis lesions on the trunk or extremities represented a homogenous vascular pattern of red dots/ globules [10][11][12][13][14]. Videodermoscopic observations of psoriasis lesions on the scalp often reveal interfollicular twisted loops, which are seen as red dots/globules at lower magnifications and as polymorphous beaded circles at higher magnifications when the probe is positioned vertically on the scalp [15].…”

“…Biopsy may be needed; even so, there are times when histopathological investigation can be inadequate for diagnosis. Dermoscopic examinations of psoriasis and seborrheic dermatitis lesions yielded different morphologies especially in the microvascular structures so it can be useful in differentiating these diseases [10][11][12][13][14][15][16][17][18][19]. In this study we investigated the usefulness of dermoscopy in the clinical differentiation of psoriasis and seborrheic dermatitis on the scalp and as distinct from previous studies, we also evaluated correlation of dermoscopic findings with disease severity.…”

Alternative uses of dermoscopy in general dermatology

“…In older lesions of lichen planus, pigmented structures may appear, thus making the vessel pattern less obvious [15] . Comedo-like structures filled with corneal content may also appear [18] . Lichen planus can be dermoscopically diagnosed by revealing the pathognomonic Wickham striae [8,19] .…”