Pathology/Lab Coding Alert

Question: A physician ordered a culture to identify the pathogen involved in a soft tissue infection on a patient's finger. What are the correct diagnosis and procedure codes?

Tennessee Subscriber

Answer: You should report the skin culture as 87070 (Culture, bacterial; any other source except urine, blood or stool, aerobic, with isolation and presumptive identification of isolates).

Presumptive identification involves "identification by colony morphology, growth on selective media, Gram stains or up to three tests (e.g., catalase, oxidase, indole, urease)," according to CPT. If the lab performs additional tests to definitively identify the organism, you should also report 87077 (Culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate).

Diagnosis varies: Regarding the correct diagnosis code, the answer depends on the type of infection. If the physician describes cellulitis to the finger, you should report one of the following codes: 681.00 (Cellulitis and abscess of finger and toe; finger; unspecified), 681.01 (... felon), 681.02 (... Onychia and paronychia of finger), or 681.9 (Cellulitis and abscess of unspecified digit).

With less specific documentation, you might report727.05 (Other tenosynovitis of hand and wrist), or 041.x (Bacterial infection in conditions classified elsewhere and of unspecified site).

If the doctor is treating an infection to soft tissue other than the skin, you could report 728.89 (Other disorders of muscle, ligament, and fascia; other).If the infection is of unknown origin or cannot be classified into these categories, you might consider 686.9 (Unspecified local infection of skin and subcutaneous tissue).

Ideally, the ordering physician should specify the location and type of infection in the coding and documentation.