Erythema chronicum migrans with an intensely purpuric border developed in a 70-year-old woman. A biopsy specimen, in addition to showing the usual perivascular mononuclear infiltrate, demonstrated numerous polymorphonuclear leukocytes associated with leukocytoclasis. Immunofluorescence study showed vascular deposition of IgM and C3.
(Arch Dermatol 115:873-874, 1979)