Cutaneous ulcerative lichen planus exhibiting pathergy, response to acitretin.

While ulcerative lichen planus is a common diagnosis when involving the mucosa, it is uncommonly found on the cutaneous surface. Cutaneous ulcerative lichen planus is usually found on the palmar or plantar surfaces and has only rarely been described elsewhere. We describe a case of cutaneous ulcerative lichen planus involving the pretibia and exhibiting pathergy, which to our knowledge has not been previously reported. We also describe successful treatment with oral acitretin in conjunction with topical and intralesional corticosteroids.