Unilateral linear lichenoid eruption after bone marrow transplantation: an unmasking of tolerance to an abnormal keratinocyte clone?

Chronic cutaneous graft-versus-host disease may appear clinically as a lichenoid eruption. We describe a 26-year-old man who developed a unilateral linear lichenoid eruption 7 months after allogeneic bone marrow transplantation. We believe this represents an unusual form of localized, chronic graft-versus-host disease. The possible relationship to viral infection or cellular mosaicism and the clinical, histologic, and immunologic similarities to idiopathic lichen planus are discussed.