Hypertrophic Lichen Planus Mimicking Verrucous Lupus Erythematosus.

Lichen planus is an inflammatory skin condition that can affect the hair, mucous membranes, nails, and skin. Cutaneous lichen planus typically presents as papules that are planar, polygonal, pruritic, and purple. Subtypes of lichen planus include actinic, annular, atrophic, eruptive, follicular, hypertrophic, inverse, linear, palmoplantar, pemphigoides, pigmentosus, ulcerative, vesiculobullous, and vulvovaginal. The various clinical presentations of lichen planus can mimic other dermatologic conditions. A 63-year-old woman, who presented with pruritic, hyperkeratotic plaques on the lower legs of two years duration, is described; her lesions were morphologically suggestive of verrucous lupus erythematosus. However, an examination also revealed purple papules on the wrists and white, reticulated patches on the bilateral buccal mucosa. Biopsies demonstrated lichenoid dermatitis while laboratory studies for systemic lupus erythematosus were negative. A correlation of the clinical presentation, pathology, and laboratory studies established a diagnosis of hypertrophic lichen planus. The clinical mimickers of hypertrophic lichen planus are reviewed and the therapeutic treatments for this condition discussed.