A 47 year old female with a past medical history of “HIV” was admitted with abscess and cellulitis of the thighs which were treated with IV Vancomycin, Ceftaz and Clindamycin. She had been recently hospitalized for disseminated herpes zoster with cervical myelitis for which she was being treated with Famcyclovir. Her herpetic lesions had become infected leading to cellulitis with abscess formation. Lab results from the previous admission included a total CD4+ lymphocyte count of 170 and she was restarted on Stribild. Outpatient records showed that she was being seen in the HIV clinic for “HIV disease” coded 042 on every encounter.

How should this record be coded?

Answer: The principal diagnosis in this case is cellulitis of the thigh (682.6) with a secondary diagnosis of herpes zoster myelitis (053.14). This patient is also HIV positive with a CD4+ count of 170 and prior outpatient visits included code 042. The current CDC definition of HIV disease (AIDS) is an HIV positive patient who has or has ever had: (1) an AIDS-defining condition and/or (2) a total CD4+ lymphocyte count <200. Official Coding Guidelines section I.C.1.(2)(f) states that once a patient has ever been assigned code 042 for HIV disease (AIDS) it must be used for all subsequent visits and never again coded V08 (asymptomatic HIV infection).

Although the patient met criteria for HIV disease, or AIDS, with a CD4+ count < 200 and previous records were coded with 042, it would be necessary to query the physician to confirm that the patient has HIV disease (042) for this episode of care because the documentation only included “history of HIV”. See Coding Clinic Third Quarter 2013 page 27.