Pathology/Lab Coding Alert

Question: Our lab processes a blood specimen using a direct probe technique for a patient with suspected Lyme disease from a tick bite. How should we code the case?

Georgia Subscriber

Answer: Report the lab test as 87475 (Infectious agent detection by nucleic acid [DNA or RNA]; Borrelia burgdorferi, direct probe technique), because Borrelia burgdorferi is the causative organism that you'd test for in a case of suspected Lyme disease.

The diagnosis coding is a little less straightforward. You should not list the diagnosis for Lyme disease (088.81, Lyme disease). The physician ordered the test for a suspected condition, so you should not code the disease as though it is confirmed.

Instead, list the diagnosis based on signs and symptoms that the ordering physician identifies. For instance, you could use a V code to show exposure: V01.89 (Contact with or exposure to other communicable diseases). You could also add E906.4 (Other injury caused by animals; bite of nonvenomous arthropod) to further define the condition that led to the need for the test.

Bottom line: If the ordering physician provides an ICD-9 code, you should list that as the ordering diagnosis. If the physician provides only a narrative, such as "tick bite, rule-out Lyme disease," you'll need to assign the most specific diagnosis known at the time of testing.