Introduction
Erythema elevatum diutinum (EED) is a kind of leukocytoclastic vasculitis, first reported by Hutchinson in 1888(1). Its typical skin lesions usually show symmetrical brownish-red papules, plaques, or lumps higher than the skin surface, which are mainly located on the extended side of the limb joints(2). It is reported that EED is associated with streptococcal infections, IgA paraproteinemia, and some malignant diseases(3).