Macular lymphocytic arteritis (MLA), also known as lymphocytic thrombophilic arteritis, is a rare medium-vessel lymphocytic vasculitis that affects the skin. It characteristically presents as multiple, asymptomatic, hyperpigmented macules on the lower extremities or as widespread, persistent livedo racemosa. MLA tends to follow an indolent course with no evidence of progression to systemic involvement.

In a review of 32 cases of MLA, the mean age of onset was 40 years, with onset ranging from 6-73 years. Women and children represented 84% and 6% of all cases that were reviewed, respectively. Individuals of African descent represented the largest ethnic group affected by MLA.

The etiology of MLA is unknown. Overlap of some histological features between MLA and certain stages of cutaneous polyarteritis nodosa (C-PAN) have raised the question of whether MLA actually exists as part of a spectrum with C-PAN.