An annular purpuric eruption secondary to a lymphocytic vasculitis with mixed features of livedoid vasculitis and lymphocytic thrombophilic arteritis

We describe three patients who presented with a striking annular purpuric eruption resulting from a lymphocytic vasculitis involving a range of superficial and deep dermal vessels. In addition to the annular purpura, two of the cases had extensive livedo racemosa, and one also had small superficial ulcers over the ankle area. Histology showed a wide range of cutaneous vascular involvement with features of both lymphocytic thrombophilic arteritis (LTA) and livedoid vasculitis (LV). Multiple biopsies and serial sections demonstrated a persistent absence of neutrophils in the infiltrate, consistent with a lymphocytic process.
Annular purpura is a novel presentation of lymphocytic vasculitis and these cases highlight the range of clinical and histological changes that may arise with this condition. They also suggest a possible relationship between LV and LTA and support the concept that a lymphocytic vasculitis can arise in the skin as a separate entity from other neutrophilic vasculitides such as cutaneous polyarteritis nodosa.

Dr. Edmund Wee