Pulmonology Coding Alert

Question: We have encountered a case of mild, intermittent asthma with an exacerbation, and our carrier could not guide us to an appropriate ICD-9 code. What is the appropriate code to report when a patient presents with mild, intermittent asthma with an exacerbation?

Arizona Subscriber

Answer: For the diagnosis of mild, intermittent asthma, you should get a record of the medical history and look for the following details: 

• Whether symptoms point specifically to asthma
• Whether there is any family history that may increase the possibility of asthma
• Whether the severity of asthma has been recorded
• Whether all possible precipitating factors have been noted.

Here, most coding experts would incline toward an“unspecified” code as the etiology or the duration of the disease is not identifiable from the diagnosis alone. The cause is very important before assigning a code here. 

Your particular case does not share your physician’s documentation details, therefore, the best advice here would be to use code 493.92 (Asthma, unspecified; with [acute] exacerbation). Unspecified asthma describes the diagnosis when no further diagnosis is available. Whenever possible, you should avoid the generalized diagnosis for a more specific one, which will result in higher reimbursement and fewer denials.

The ICD-9 manual does lack a specific code for mild, intermittent asthma. Rather, asthma is broadly classified under 493.x with several sub-classifications, including the following, among others:

• 493.0x -- Extrinsic asthma
• 493.1x -- Intrinsic asthma
• 493.2x -- Chronic obstructive asthma
  
• 493.8x -- Other specified asthma
• 493.9x -- Asthma, unspecified.

The fifth digit should be “0” if the patient has no acute symptoms and “2” if the patient has acute exacerbation. Codes 493.0x and 493.1x imply the existence of specific etiologies (causes) for the asthma.

Next year onward, you will find it easier to solve these conundrums as ICD-10 nomenclature has tried to address this discrepancy to some extent with introduction of codes for cases that involve “exacerbation in mild asthma” with codes J45.21 (Mild intermittent with [acute] exacerbation), J45.31 (Mild persistent with [acute] exacerbation) and J45.41 (Moderate persistent with [acute] exacerbation)