classically , it is characterized by violaceous polygonal pruritic papules . localized hyperpigmentation of palms is a rare presentation of lichen planus . lichen planus is a chronic inflammatory skin eruption chiefly occurring in the middle age , i.e. , 30 - 60 years of life , with no sex or racial differences . palmoplantar involvement is seen rarely with lichen planus and often does not have the classically morphology , making it difficult to establish the diagnosis . till date , there is a single case report of palmar lichen planus mimicking superficial fungal infection  tinea nigra . a 45-year - old healthy housewife presented to our opd for an opinion on asymptomatic black colored patches present on both palms of two months duration . she also did not give history of any high risk sexual behavior or genital ulcer disease . cutaneous examination showed a single , well - defined black - colored patch on the right hypothenar surface and three brownish colored patches on the left hypothenar eminence [ figure 1 ] . we considered a differential diagnosis of tinea nigra , resolved fixed drug eruption , pigmented contact dermatitis , and exogenous pigment . well defined black to brownish colored patches on both the hypothenar eminences of palms contact dermatoscopy of pigmented patch showed a hem - like pattern of pigment distribution along the ridges of the dermatoglyphics [ figure 2 ] . after obtaining informed consent , a biopsy was taken from one of the representative lesion under local anesthesia and was fixed in 10% buffered formalin . a hematoxylin and eosin stained section of skin biopsy showed hyperkeratotic stratum corneum and acanthotic epidermis with vacuolar changes of the basal layer . a band - like infiltrate comprising lymphohistiocytic infiltrate was evident at the dermo - epidermal junction [ figure 3 ] . gomori  methenamine silver ( gms ) stain of skin biopsy did not show presence of fungal hyphae . we prescribed topical clobetasol propionate ( 0.05% ) cream along with white soft paraffin to be applied twice daily . the patient responded completely to the topical steroid cream and emollients [ figure 4 ] . dermatoscopy of palmar lesion showing brown colored pigment along the ridges of dermatoglyphics in a hem like pattern h and e stained section of skin biopsy from the lesion showing hyperkeratotic stratum corneum , vacuolar change of basal layer with interface dermatitis composing of lymphocytic infiltrate abutting the basal layer . ( 20 ) same patient six weeks after treatment with topical steroids and white soft paraffin palmoplantar lichen planus is a localized and rare variant of lichen planus . palmoplantar involvement in lichen planus was seen in 26% of their case series in a study done by sanchez - peres and colleagues . in contrast to classical lichen planus , lichen planus of palms and soles does not demonstrate wickham 's striae and its typical polygonal lesion . the characteristic morphology of palmar and plantar lichen planus is that of pruritic papules and plaques , which are erythematosus and scaly with well - defined borders . other clinical variants of palmoplantar lichen planus include pitted plaques , ulcerative lesions , vesicle - like papule , umbilicated papules , punctate keratoderma , perforating palmar lichen planus , and petechiae - like lesions . the differential diagnosis for palmoplantar lichen planus includes verruca vulgaris , psoriasis , callus , punctate palmoplantar keratoderma , arsenical keratosis , papular syphilides , kyrle disease , acrokeratosis paraneoplastica ( bazex syndrome ) , punctate porokeratosis , lichen simplex chronicus , and eczematous hand dermatitis . however , in contrast , our patient had non - itchy and non - palpable macular eruption with well - defined margins . in 2009 , mehta et al . had reported similar palmar pigmentation , which was proved to be lichen planus on histopathology . reported hyperkeratotic palmar lichen planus associated with clenched fist , which resolved after topical salicylic acid and methylprednisolone ointment . in our case , we considered a differential diagnosis of tinea nigra and exogenous pigment deposition ( argyria ) . on closer inspection , we were able to notice that each of the patches had dot - like pigmentation involving the ridges more prominently and the same was confirmed with dermatoscopy . diagnosis of isolated palmoplantar lichen planus is difficult , as it does not present with the classical violaceous papules and lacks wickham 's striae ; thus , it can create a diagnostic confusion if other classical features are not evident elsewhere . on clinicopathological correlation , we reached the diagnosis of palmar lichen planus mimicking tinea nigra . the patient was counselled about the benign nature of the condition and was advised to apply topical steroid and emollients . to conclude , we report a case of palmar lichen planus with atypical presentation of localized pigmentation simulating tinea nigra .
lichen planus ( lp ) is a chronic inflammatory skin disease characterized by polygonal , violaceous papules commonly involving flexural areas of the wrists , legs , and oral and genital mucous membranes . 
 this report describes a patient who presented with asymptomatic black colored patches on both palms simulating tinea nigra , a superficial fungal infection . 
 she was previously diagnosed as allergic contact dermatitis and was being treated with potent topical steroid i.e. clobetasol propionate 0.05% and white soft paraffin . 
 dermatoscopy of the lesion showed brownish pigmentation along ridges of the dermatoglyphics . 
 a biopsy from the lesional skin showed findings of lichen planus . 
 our case highlights the potential diagnostic confusion that can occur with unusual variants of palmoplantar lichen planus and importance of histopathology in diagnosis of such unusual lesions .