Hemophagocytic Lymphohistiocytosis Secondary to Anaplasmosis With Lyme Coinfection

Abstract

Human granulocytic anaplasmosis and Lyme disease are tick-borne infections transmitted by the same vector, Ixodes scapularis, commonly isolated in areas within the Midwest region of the United States. Although typically associated with mild symptoms, both can progress to severe disease. Treatment of choice for a majority of tick-borne illness is doxycycline; however, options are limited in the setting of tetracycline allergy. Here, we present a complex case of human granulocytic anaplasmosis–induced hemophagocytic lymphohistiocytosis complicated by coinfection with Lyme encephalitis in a patient with a documented tetracycline allergy.