This otherwise healthy young woman presented with papules and nodules on her forearms, wrists, and hands. Erythema elevatum diutinum is extremely rare and its etiology unknown, although there have been reports following viral illness, injections, and systemic disease. There are two stages of an individual lesion. Early findings are that of leukocytoclastic vasculitis. Later, as the lesion organizes, it becomes large and fibrotic, almost keloidal. Histologically, these can be mistaken for tumors, including sclerotic fibromas. However, there is an inflammatory component and sometimes vasulitis in the lesion, both unusual for tumors. It probably is more akin to a nodular fasciitis.
The low power view shows leukocytoclasia and numerous extravasated red blood cells. The infiltrate appears restricted to the superficial dermis.