Clinical and Dermoscopic Study of Palmoplantar Keratodermas
Authors: Rajeendran Atul , Shenoy Manjunath Mala , Pinto Malcolm , Amin Vishal B , Hegde Spandana Prakash , Asfiya Amina , Razak Ashmiya Abdul 
Published: November 2023

Background: Palmoplantar keratodermas (PPK) represents a group of skin disorders characterized by excessive epidermal thickening of palms and soles. They are classically divided into inherited and acquired groups. Dermoscopy is a non-invasive procedure that can aid in the clinical diagnosis of PPK. Objectives: To study the clinical features and dermoscopic patterns of PPK caused by various dermatological conditions. Methods: Ninety-eight patients with various types of PPK were included in this cross-sectional observational study after obtaining informed consent. Symptoms, general systemic findings, and dermatological manifestations were recorded. The dermoscopic examination was performed by a single observer using Heine Delta 20+ and FotoFinder Medicam 1000. Diagnostically challenging cases were biopsied for histopathological examination. SPSS (Statistical Package for Social Sciences) version 20 [IBM SPSS statistics (IBM Corp. Armonk, NY, USA released 2011)] was used to perform statistical analyses. The chi-square test was applied to examine statistical associations between qualitative variables. The level of significance was set at 5%. Results: Out of 98 cases with PPK, 93 were acquired, and 5 were inherited. The commonest dermoscopy pattern included palmoplantar psoriasis (n = 48), showing a background light red color with yellow diffused white scales with regular dotted and glomerular vessels, followed by palmoplantar eczema (n = 39) (light red color with yellow patchy white background, yellow scales, and patchy dotted vessels). Light red/dull red background with diffuse white scaling and regular linear, dotted, or glomerular vessels were significantly in favor of palmoplantar psoriasis, while a yellow background, diffuse yellow scaling, patchy dotted vessels, and yellow crust were more in favor of palmoplantar dermatitis. Pityriasis rubra pilaris (PRP) (n = 3) showed a light red background, diffused white scales, and dotted and linear vessels with patchy distribution. Lichen planus (n = 2) revealed a light red color with a yellow background, diffused and peripheral white scales, and irregular linear (radial) and dotted vessels. Wickham’s striae were found on palms. Tinea manuum with pedis (n = 1) showed a dull red background and diffused white and yellow scales with the localization of the scales in the skin furrows. Palmoplantar keratodermas secondary to ichthyosis vulgaris (n = 3) revealed a light red background with diffused white and yellow patchy scaling and regular linear and patchy glomerular vessels. Greither’s disease showed a light red color with a yellow background, a diffused white scale pattern, and multiple dotted vessels arranged in an irregular pattern. Erythrokeratodermia variabilis showed a background color of light red and diffused white scales in a crisscross pattern. Conclusions: Dermoscopy can reveal characteristic but not pathognomonic dermoscopic patterns that can be useful in the clinical diagnosis of various types of PPK. More studies with larger sample sizes may help validate these findings and identify new patterns.