Palmar lichen planus mimicking 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.