The histologic examination revealed arteritis of a medium-sized arteriole in the deep reticular dermis. There was fibrinoid degeneration of the arterial wall. A primarily neutrophilic infiltrate was present in and around the vessel wall.
A thorough evaluation showed no visceral involvement. Stool and urine samples were negative for occult blood; results of liver function tests were normal; and serologic tests were negative for hepatitis B. The findings of the remainder of her physical examination were normal. Oral prednisone therapy (60 mg/d) was initiated.
Purpuric Nodules and Macules on the Extremities of a Young Woman. Arch Dermatol. 1998;134(2):231-236. doi: