Lichen planus showing columnar epidermal necrosis.

We describe a 9-year-old boy who presented with very itchy papules and plaques on both knees. Histologically, focal columnar epidermal necrosis was seen associated with features of classic lichen planus. A literature search using PubMed revealed that only two cases of transfusion-associated lichenoid graft-versus-host reaction showing columnar epidermal necrosis have been previously reported. Our case is the first of lichen planus showing columnar epidermal necrosis. In that lichenoid graft-versus-host reaction is a special form of lichen planus, it is possible to speculate that columnar epidermal necrosis may be a unique feature of lichen planus.