Unilateral Lichen Planus : A Rare Case Report

Lichen planus (LP) is a papulosquamous disorder characterized by violaceous, flat topped papules and plaques seen on the volar aspect of the wrists, lumbar region and around the ankles. It can have a varied presentation. Here we describe a rare variant of LP in a female who presented with unilateral eruptions of violaceous papules over the right side of the body.


Introduction
L ichen planus (LP) is an infl ammatory disorder of unknown e ology that aff ects skin, mucous membranes and nails. 1,2It is characterized by development of pruri c, fl at topped, violaceous papules with white re culate network referred to as Wickham's striae. 3The lesions are distributed symmetrically and bilaterally over extremi es.It tends to involve the fl exor aspect of the wrist, arms and legs.Many variants of this disorder like papular, hypertrophic, erup ve, annular, linear, atrophic, erosive, vesiculobullous etc. have been described. 3,4Here we report a rare variant of this disorder in a 30-year-old female, who presented to our skin outpa ent department with unilateral erup on of violaceous papules over the right side of the body.

Case report
A 30-year-old female presented with history of mul ple, asymptoma c, slightly raised violaceous lesions on the right arm, forearm, breast and thigh for the past 3 years.The erup on of the lesions was not preceded by any trauma, dental treatment or any drug intake.Pa ent gave a history of selfresolu on of some of these lesions which le behind residual hyperpigmenta on.Pa ent had no other comorbidi es.
On examina on, mul ple violaceous, plane topped papules were no ced on the right arm and forearm (Figure 1).Post infl ammatory hyperpigmenta on was no ced on the right breast and the right thigh (Figure 2,3).Some of these lesions showed Wickham's striae.Examina on of nails, scalp, oral and genital mucosa revealed no lesions.
A provisional diagnosis of unilateral LP was made and a skin biopsy was sent for histopathological examina on (HPE) from one of the representa ve lesions on the right forearm.HPE revealed moderate hyperkeratosis and mild irregular acanthosis.Basal cell degenera on and saw toothing of rete ridges was seen.The upper dermis showed a moderately dense lymphocy c infi ltrate abu ng the basal layer of the epidermis.Apopto c kera nocytes and pigment incon nence was also no ced (Figure 4).
A fi nal diagnosis of unilateral LP was made.Pa ent was started on topical steroids, emollients and an histamines and showed improvement.

Discussion
Several variants of LP have been described but unilateral LP is a very rare presenta on.The presence of lesions only on the right side of the body in this pa ent and a strict demarca on of these lesions at the midline cannot be explained.Few cases of unilateral LP along the lines of Blaschko have been described in the literature. 2,3,5,6Unilateral oral LP has also been decribed. 7However, in our pa ent the lesions did not strictly confi ne to the Blaschko's lines.

Conclusion
Unilateral Lichen Planus is a rare disease but it is important to diff eren ate it from other naevoid disorders because licen planus responds to therapy. http://dx.doi.org/10.3126/njdvl.v16i1.19419

Figure 2 :
Figure 2: Residual hyperpigmenta on of lichen planus lesions on the right thigh.

Figure 3 :
Figure 3: This fi gure shows presence of the lesions only on the right breast and sparing of the le breast.

Financial disclosure:
None.Confl ict of interest to disclosure: None declared.