Recurrent annular erythema with purpura: a new variant of leucocytoclastic vasculitis responsive to dapsone.

Annular lesions are rarely reported in the clinical spectrum of leucocytoclastic vasculitis, except in the acute haemorrhagic oedema of the skin. We report three patients who suffered from an extraordinary recurrent annular dermatitis, for 4 years in one case and for decades in the other two. The eruption was characterized by purpuric lesions that had a centrifugal evolution, creating target- or polycyclic patches disseminated on the limbs and trunk. The patients' general condition remained excellent during the attacks. All lesions spontaneously disappeared within 2 weeks, but recurred monthly. In all three cases, the histological changes were consistent with leucocytoclastic vasculitis. One patient had ulcerative colitis and another had a benign immunoglobulin A (IgA) monoclonal gammopathy. These two patients showed a good response to dapsone therapy. This dermatosis probably represents a new and rare variant of leucocytoclastic vasculitis.