Livedo racemosa in lymphocytic vasculitis.

Abstract

A 24-year-old female presented with a 10-year history of mottled patches on the limbs. These were asymptomatic and persisted on rewarming. She was otherwise well with no past history or constitutional symptoms. Examination revealed reticulate erythematous to cyanotic patches forming incomplete rings, consistent with livedo racemosa. Histology showed a lymphocytic vasculitis with 1+ granular deposits of C3, IgM and fibrin on direct immunofluorescence. Clinical systemic review, antiphospholipid, hypercoagulability and autoimmune workups were unremarkable. This was consistent with the diagnosis of lymphocytic thrombophilic arteritis, a medium vessel vasculitis typically without systemic involvement. This presents with livedo racemosa, which is differentiated from livedo reticularis by the presence of larger broken rings that do not reverse with warming. Unlike livedo reticularis which may be physiological, livedo racemosa is always pathological. Critically, a skin biopsy should include the centre of the ring in order to sample the feeding artery.