Dermoscopic Nail Changes in Psoriasis, Lichen Planus, and Lichen Striatus

Background: Onychoscopy is a noninvasive method helpful in diagnosing nail disorders. The aim of the study was to review literature on the usability of onychoscopy in nail psoriasis, nail lichen planus, and nail lichen striatus. Summary: Onychoscopic features of nail psoriasis are pitting, onycholysis with erythematous border, salmon patches, splinter hemorrhages, dotted vessels in lateral and proximal folds, and hyponychium. Onychoscopic features of nail lichen planus are onychorrhexis, onycholysis, longitudinal melanonychia, and red lunula. The literature on the usability of onychoscopy in nail lichen striatus is scarce. Keynotes: Onychoscopy facilitates evaluation of nail abnormalities compared to the clinical examination. Lunular alterations, salmon patches, erythematous border of onycholysis as well as splinter hemorrhages in nail psoriasis are better visualized with onychoscopy compared to the naked eye. Onychoscopy enhances detection of melanonychia, dyschromia, and lunular changes in nail lichen planus. Onychoscopic features are different in fingernails and toenails. Onychoscopy (nail dermoscopy) is a noninvasive method used in diagnosing of nail disorders. In this review, we evaluated if onychoscopy may be helpful in diagnosing inflammatory nail disorders such as psoriasis, lichen planus, and lichen striatus. Nail psoriasis can be characterized with the presence of pitting, salmon patches, splinter hemorrhages, onycholysis with or without erythematous border and dilated vessels in the hyponychium on onychoscopy. Onychoscopy of nail lichen planus shows the presence of longitudinal ridging and splitting (onychorrhexis), splinter hemorrhages, longitudinal melanonychia as well as red lunula (distal part of nail matrix). The data on onychoscopy in nail lichen striatus are scarce. Onychoscopy is a helpful tool in visualization of nail abnormalities, with most of the features better visualized with onychoscopy compared to the naked eye.