Koebnerization as a cutaneous manifestation of immune complex-mediated vasculitis.

Two unusual examples of the cutaneous manifestations of vasculitis are presented. In both cases lesions occurred on previously traumatized skin and on normal skin of the dependent areas. Lesional skin biopsy specimens obtained from the koebnerized sites and from the other dependent sites revealed evidence of vascular injury in both patients. A diagnosis of leukocytoclastic vasculitis was made in one patient and pityriasis lichenoides et varioliformis acuta in the other. Direct immunofluorescence microscopy of lesional skin specimens from both patients demonstrated dermal vascular immune deposits. Raji cell assay detected a significant elevation of circulating immune complexes in the serum of both patients. Neither koebnerizing leukocytoclastic vasculitis nor koebnerizing pityriasis lichenoides et varioliformis acuta has been reported previously.