Histopathological evaluation of nail lichen planus: A cross‐sectional study

Abstract

Introduction: Up to 10% of patients with lichen planus (LP) have nail involvement; still there is a paucity of studies on histopathological features. Nevertheless, nail biopsy is the diagnostic standard, especially for isolated nail LP. Methodology: Nails of 45 patients with nail LP were evaluated clinically and biopsies taken from most involved nail (25 nail bed and 20 matrix biopsies). Correlation of clinical and histopathological features was also done. Results: The mean age of the study group participants was 36.91 ± 18.27 years with a M:F ratio of 1.81:1. The most common clinical variant of LP seen was oral LP (51%), with isolated nail involvement in 29%. Clinically, major features were onychorrhexis (92.3%), longitudinal melanonychia (74.3%), and nail bed erythema (54%). Histopathologically, hypergranulosis of nail matrix and bed epithelium (51.1%), followed by sawtooth acanthosis (44.4%) and lichenoid band (24.4%) were most common. A diagnosis using prevalent diagnostic criteria was confirmed in 51.1% biopsies. Distinctive "fraying of nail plate," a change not previously described, was noted in 33.3% cases. Conclusion: Histopathology of nail LP has been attributed a diagnostic role; however, existing diagnostic criteria are not sensitive enough and need refinement. Not hitherto described features like fraying of nail plate are seen in a significant number of cases. K E Y W O R D S lichen planus, nail bed biopsy, nail lichen planus, nail matrix biopsy 1 | INTRODUCTION Nail involvement can be seen in up to 10% of patients with lichen planus (LP), 1-7 with permanent nail dystrophy or nail loss occurring in approximately 4% of patients. 4 Nail LP is often associated with involvement of other mucocutaneous sites, 8 though isolated nail involvement can be seen in a significant number of cases. The disease affects fingernails more often than toenails, 9 involving two to three fingernails initially. 9 Distinctive clinical variants of nail LP include nail matrix disease, nail bed disease, trachyonychia, idiopathic atrophy of the nails, and bullous-erosive LP. 10-12 Although any part of the nail unit 4,13 can be involved, the matrix is preferentially involved. 14 Nail bed involvement has been reported to be more common in toenails as compared to fingernails. On the other hand, matrix involvement is more commonly seen in fingernails. 8,13 LP of nail matrix is a slowly progressive but potentially scarring disease, dreaded complications being permanent anonychia and pterygium formation. Hence, an early diagnosis and appropriate therapy are of utmost importance.

Clinical features and treatment outcomes of nail lichen planus: A retrospective study

“…Most of the patients in the present study (85.7%) had melanonychia. This finding is consistent with a study in India by Kharghoria et al, 4 which reported that 88.9% of their patients had melanonychia. Multiple studies have observed that postinflammatory melanonychia is found with many inflammatory nail disorders, such as nail lichen planus, psoriatic nail, chronic paronychia, and traumatic nail.…”

“… 1 , 2 Approximately 4% of nail lichen planus cases result in permanent nail scarring. 4 The present study showed that 10% of patients with lichen planus had the characteristics of nail lichen planus, which is similar to the findings of earlier investigations. 1 , 2 …”

Ultrasound Features of Nail Lichen Planus

“…Moreover, inflammatory histological findings have been reported on NLP, and these include hypergranulosis of the nail matrix and bed epithelium, sawtooth acanthosis, irregular epidermal hyperplasia, a lichenoid infiltrate with the formation of Civatte bodies, vacuolar degeneration of the basement membrane, and pigmentary incontinence. 19,20 Isolated nail bed involvement in NLP is rarely seen. In our sample, no patient presented with single nail bed involvement; nevertheless, the ultrasound examination showed subclinical findings in multiple nails ("halo sign" and inflammatory signs in the nail bed and proximal nail fold).…”

“…The prominent ultrasonographic signs of inflammation surrounding the nail plate origin and involving the nail matrix region can explain why NLP is so destructive of the nail unit and how a clinical pterygium, which implies the presence of scarring, can appear in this entity. Moreover, inflammatory histological findings have been reported on NLP, and these include hypergranulosis of the nail matrix and bed epithelium, sawtooth acanthosis, irregular epidermal hyperplasia, a lichenoid infiltrate with the formation of Civatte bodies, vacuolar degeneration of the basement membrane, and pigmentary incontinence 19,20 …”

The “frayed nail plate” and further detailed analysis of the histopathologic features of nail unit lichen planus

“…In this issue of our Journal of Cutaneous Pathology , Kharghoria and colleagues 1 present data from a cross‐sectional study of 45 patients with nail unit lichen planus. Biopsy specimens included 25 of the nail bed and 20 of the nail matrix.…”