Lichen planus pigmentosus-inversus involving the post-auricular sulci.

Lichen planus pigmentosus-inversus is rare with only twenty patients (including our patient) formally described in the literature. The reported twenty patients with lichen planus pigmentosus-inversus include eight men and twelve women with ages ranging from 25-84 years (average age of 55.3). Twelve were Caucasian, five were Asian, one was Hispanic and two were of unknown ethnicity. Seventeen out of twenty patients had lesions in the axillae and mild pruritus was present in eight patients. Our patient is the first patient reported to have post-auricular sulcus involvement.