Pathology/Lab Coding Alert

Question: The physician orders an RSV test for a 2-year-old patient presenting with shortness of breath and a cough. The lab performs an antigen detection test with positive findings. What are the correct procedure and diagnosis codes?

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Answer: A laboratory might perform an antigen detection test for respiratory syncytial virus (RSV) using several different methods. You’ll need to know how the lab performs the test if you want to assign the correct procedure code. For instance, a clinical lab might carry out one of the following tests:

• 87280 (Infectious agent antigen detection by immunofluo­rescent technique respiratory; syncytial virus)
• 87420 (Infectious agent antigen detection by immunoassay technique (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], fluorescence immunoassay [FIA], immunochemiluminometric assay [IMCA]), qualitative or semiquantitative; respiratory syncytial virus)
• 87634 (Infectious agent detection by nucleic acid (DNA or RNA); respiratory syncytial virus, amplified probe technique)

A physician office lab is more likely to perform an RSV test using 87807 (Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation; respiratory syncytial virus)

Because the lab reports the ordering diagnosis as the reason for the test, you would list the following codes based on the physician’s order:

• R05.1 (Acute cough)
• R06.02 (Shortness of breath)

If the lab test is positive for RSV, the ordering physician will use that data along with clinical information to assign a final diagnosis. Because RSV may cause respiratory infections such as bronchitis, or ear infections, or infections at other sites, the final diagnosis will be the code for the site of the infection, plus a second code to indicate RSV as the source using B97.4 (Respiratory syncytial virus as the cause of diseases classified elsewhere).