Relapsing fever, unspecified

This code represents a systemic infectious disease characterized by recurrent episodes of fever, often accompanied by headache, muscle aches, and rash. It is caused by spirochetes of the Borrelia genus, transmitted by ticks or lice. The "unspecified" nature indicates that the specific type of relapsing fever (e.g., louse-borne or tick-borne) is not documented.

Use this code when a patient presents with clinical signs and symptoms consistent with relapsing fever, but the medical record does not specify the vector or the particular Borrelia species involved. This diagnosis is typically supported by a physician's documentation of "relapsing fever, unspecified" or similar terminology when further specificity is unavailable.

• Avoid using this code if the documentation clearly specifies louse-borne or tick-borne relapsing fever; use the more specific codes.
• Ensure the documentation supports the diagnosis of relapsing fever, even if the type is unspecified.
• Consider sequencing this code as the primary diagnosis if it is the reason for the encounter.