Lichen striatus with nail involvement

Introduction

Lichen striatus (LS) is a self-limited, linear papular dermatosis of unknown etiology seen primarily in children between the ages of 4 months and 15 years. Clinically it is seen as unilateral, asymptomatic, flesh-colored to red-brown flat topped papules that follow Blaschko lines.[1],[2],[3]

Nail involvement in LS is uncommon. In this paper we report a case of LS with nail changes.

Case Report

A 13-year-old boy presented to skin OPD with asymptomatic linear rash over right upper limb, including right thumb nail. Cutaneous examination revealed pink and flesh -coloured papules and plaques at places with overlyintg thin scales. Right thumb nail showed nail thinning, longitudinal ridging and splitting restricted to the lateral portion. Skin biopsy revealed focal epidermal spongiosis with perivascular lymphohistiocytic infiltrate in the papillary dermis. Patient refused for planned longitudinal nail biopsy.

Discussion

Nail involvement in LS is uncommon and has always been associated with typical skin lesions.[3],[4],[5],[6] Survey of available literature revealed 20 cases of nail lichen striatus reported.[6] Tosti et al[6] reported two cases of LS limited only to the nails. Logitudinal ridging and splitting were common clinical features of nail involvement in LS, as in the present case. A nail biopsy is necessary only when a nail matrix tumor is considered in the differential diagnosis, because the diagnosis of LS is usually based on the presence of skin lesions.

Based on survey of available literature and present case, we propose following criterion for nail LS-longitudinal ridges and splitting localised to medial or lateral portion of nail, single nail involvement, and presence of skin lesion near the nail. The last point is in contrast to lichen planus, where nail changes occur when generalised lichen planus and therefore not necessarily any skin lesion near the nail.