Lyme carditis in an immunocompromised patient.

We present a case of a 68-year-old man with a history of liver transplant and of chronic immunosuppression therapy who presented to the emergency department (ED) for fevers and worsening fatigue for two days. On further investigation, the patient was found to have a new first-degree heart block on his electrocardiograph. Coupled with the history of a recent tick bite, the patient was diagnosed with vector-borne carditis. Although the patient's titers for various vectors remained negative, due to a long history of immunosuppression, he was treated for Lyme disease and his heart block completely resolved with antibiotic treatment. We describe details of the case as well as discuss the impacts of immunosuppression on vector-borne disease. Immunosuppressed patients represent a special population and can present with chief complaints made even more complicated by their medical history, and this case illustrates the importance of being mindful of how immunosuppression can affect a patient's presentation. As the efficacy of antirejection medications improved, the ED may see an increasing number of patients with solid organ transplants. A greater understanding of this special patient population is key to formulating optimal treatment plans.