Colorado tick fever in a resident of New York City.

When a traveler returns from abroad with a febrile illness, clinicians appropriately concern themselves with a potentially vast array of diagnostic exotica. The patient we describe herein did not leave the United States but nevertheless posed the same clinical dilemma after returning home to New York City from the western United States. This case of Colorado tick fever, acquired on the Utah-Colorado border and first expressed in Manhattan, serves as a useful reminder of the importance of taking a careful travel history for national as well as international travelers.