Tennessee Subscriber Answer: Although looking up -Sinusitis: due to: fungus, any sinus- in the Alphabet Index, Volume 2 of ICD-9-CM directs you to -117.9,- a single code doesn't describe fungal sinusitis. You should instead use a combination of ICD-9 codes to represent the condition.
-Use additional code to identify manifestation,- according to the initial instruction for category 110-118, Mycoses. For the primary diagnosis, list the chronic or acute sinusitis. Then code the underlying fungal infection as the secondary diagnosis. Here's how:
Step 1: Report the appropriate sinusitis code for sinus membrane lining inflammation. Use 461.x for acute sinusitis. For chronic sinusitis -- frequent or persistent infections lasting more than three months -- assign 473.x. Choose the fifth-digit code based on where the sinusitis occurs. For example, for ethmoidal chronic sinusitis, you should report (473.2, Chronic sinusitis; ethmoidal). Your otolaryngologist will most likely prescribe a decongestant, pain reliever or antibiotics to treat sinusitis.
Step 2: Assign the ICD-9 code that represents the fungal infection. Category 117 lists several types of mycoses that offer a more specific diagnosis than 117.9 (Other and unspecified mycoses). For instance, suppose a patient has ethmoidal sinusitis due to aspergillosis (117.3), an infection that can affect the sinuses and is caused by inhaling the fungus aspergillus, which is found in compost heaps, air vents and airborne dust. Enter 473.2 as diagnosis 1 and 117.3 as diagnosis 2 in Box 21 of the CMS-1500 form.
Although the otolaryngologist may treat aspergillosis with antifungal drugs, such as amphotericin, itraconazole or voriconazole, some forms of aspergillus resist these drugs. So the physician may need to treat the patient with caspofungin, a newer antifungal drug. Your otolaryngologist can treat more serious aspergillosis cases in the sinuses by scraping out the fungus (31237, Nasal/sinus endoscopy, surgical; with biopsy, polypectomy or debridement [separate procedure]) and applying antifungal drug drops.