Relapsing fever, tick-borne

This code signifies a recurrent febrile illness caused by spirochetes transmitted by ticks. Patients typically experience episodes of high fever, headache, myalgia, and arthralgia, followed by afebrile periods, due to antigenic variation of the causative organism.

Assign this code for documented cases of relapsing fever where tick exposure is identified or strongly suspected as the mode of transmission. Supporting documentation should include a history of tick bite, characteristic relapsing fever patterns, and/or laboratory confirmation of Borrelia species associated with tick-borne disease.

• Differentiate from louse-borne relapsing fever, which has a distinct ICD-9-CM code.
• Ensure documentation specifies "tick-borne" to justify this specific code.
• Consider sequencing this code as the primary diagnosis if it is the reason for the encounter.