Tickborne diseases other than Lyme in the United States.

Tickborne diseases are increasing in the United States, and the geographic range of tick vectors is expanding. Tickborne diseases are challenging to diagnose, as they present with vague symptoms such as fever, constitutional symptoms, and nonspecific laboratory abnormalities. A high degree of clinical suspicion is required to make a diagnosis, as patients often do not recall a tick bite. The availability of laboratory testing for tickborne diseases is limited, especially in the acute setting. Therefore, if a tickborne disease is suspected, empiric therapy should often be initiated before laboratory confirmation of the disease is available. This article summarizes the most common non-Lyme tickborne diseases in the United States.