Dont Stress Out When Coding Hypersensitivity Pneumonitis

Relax coding for hypersensitivity pneumonitis can put even the most experienced coder into a frenzy. Navigate your way through the whirlwind of diagnoses, E/M and procedures codes with this detailed map.
For starters, you have to know exactly what you're coding for. When a patient suffers a Type III allergic reaction to environmental allergens and develops local inflammation caused by tissue damage, the diagnosis is hypersensitivity pneumonitis, an inflammatory lung disorder often referred to as extrinsic allergic alveolitis (EAA). Watch out for hypersensitivity pneumonitis if your practice is in certain areas of the country, such as cities with nearby farms or factories. The disease is the result of long-term or intense exposure to environmental antigens, such as inorganic dust and other occupational antigens, says Jeffrey Berman, MD, FCCP, executive director of the Florida Pulmonary Society.

The steps a physician takes to properly diagnose hypersensitivity pneumonitis may complicate your coding, but they shouldn't block your reimbursement. Here's the lowdown on finding the diagnoses codes that lead to payment.
Sift Through the Many Diagnosis Options
Recognizing the disease's symptoms will help you to report the proper diagnosis code, one that matches the in-depth tests the allergist needs to diagnose EAA. Symptoms can include fever (780.6), shortness of breath (786.05), chest pain (786.50), weight loss (783.21) and fatigue (780.79), says Anthony Marinelli, MD, FCCP, chairman of the American Thoracic Society's Clinical Practice Committee.

Once the physician has definitively diagnosed the patient with EAA, you should code to the highest level of specificity. The ICD-9 manual covers EAAin the 495 series (Extrinsic allergic alveolitis) and differentiates between antigens by using a fourth digit:

495.0 Farmers'lung

495.1 Bagassosis

495.2 Bird-fanciers'lung

495.3 Suberosis

495.4 Malt workers'lung

495.5 Mushroom workers'lung

495.6 Maple bark-strippers'lung

495.7 "Ventilation" pneumonitis

495.8 Other specified allergic alveolitis and pneumonitis

495.9 Unspecified allergic alveolitis and pneumonitis.

Code for E/M and Other Procedures Separately
Pay close attention to documentation details that secure maximum reimbursement for E/M services, which most physicians perform before diagnosing a patient with hypersensitivity pneumonitis.

The patient usually presents with varying symptoms that can be confused with other respiratory problems, so the allergist must take an extensive history, perform a thorough exam and order several diagnostic tests. "In pulmonary medicine, it is thought that 70 percent of the time the patient's history gives the diagnosis," Marinelli says.

For example, a 35-year-old male presents in the office with symptoms that include a cough (786.2), fever (780.6), fatigue (780.79) and weight loss (783.21). A physical exam may reveal crackles in the lung (786.7), wheezing (786.07) and shortness of breath [...]

- Published on 2003-03-01