Pulmonology Coding Alert

Question: Are multiple codes applicable for chronic obstructive pulmonary disease (COPD), and have there been recent changes to the applicable codes?
Maine Subscriber   Answer: COPD (496) is a general term for many disorders that cause persistent obstruction of bronchial airflow. Covered by 496 are non-specific lung disease, obstructive lung disease and obstructive pulmonary disease. It should not, however, be used when bronchitis, emphysema or asthma applies. These exceptions fall under categories 491.xx (chronic bronchitis; chronic must be specified), which includes 491.0 (simple chronic bronchitis or smoker's cough), 491.1 (mucopurulent chronic bronchitis, persistent inflammation of the bronchi with mucous) and 491.2x (obstructive chronic bronchitis, with or without acute exacerbation), as well as 492.x (emphysema) and 493.xx (asthma; intrinsic, extrinsic, chronic-obstructive or unspecified). The "xs" indicate subcodes and you should not assume that emphysema, for example, can be coded with only three digits instead of four. Missing digits in your diagnosis will cause an automatic rejection of the claim. 
New codes for 2001 include 493.02 (extrinsic asthma, with acute exacerbation, i.e., allergic response to pollen, house dust, animal dander, molds, food, beverages, vapors or drugs), 493.12 (intrinsic asthma with acute exacerbation, non allergic category, emotional stress, fatigue, endocrine changes), 493.22 (chronic obstructive asthma with acute exacerbation) and 493.92 (unspecified asthma with acute exacerbation).