Consider Lyme carditis in children who present with acute carditis of unknown cause with appropriate epidemiologic history. Serum antibody testing is preferred. PCR testing or culture of blood has poor sensitivity and is not generally recommended. Treatment for children of all ages may consist of one of the following regimens: Ceftriaxone (intravenous) for 14-21 days Doxycycline for 14-21 days Amoxicillin for 14-21 days Cefuroxime for 14-21 day Please refer to the 2020 Guidelines for the Prevention, Diagnosis and Treatment of Lyme Disease for specific treatment and dosing information.