Macular lymphocytic arteritis: a unique benign cutaneous arteritis, mediated by lymphocytes and appearing as macules

Abstract

Macular arteritis (MA) is a term coined for a cutaneous vasculitis that manifests as multiple macules that favor the lower extremities and that reveal lymphocytic inflammation of an artery in the deep dermis and subcutaneous fat. We describe the demographic, clinical, histologic, and laboratory findings in three new cases and review seven previously reported cases of MA, and discuss the nosology of MA. MA affects predominantly females (70% or 7/10) and individuals of African-American race (50%). Eight patients had hyperpigmented patches, one had hypopigmented macules, and one had erythematous macules. The lower extremities were involved in 100% of cases, followed by the upper extremities (44%). Light microscopic changes are those of a medium-vessel lymphocytic arteritis. Investigations for possible causes are non-revealing. We conclude that MA is a primary idiopathic cutaneous lymphocytic arteritis that is limited to the skin.