CHICAGO – Community physicians can feel comfortable diagnosing and treating hypersensitivity pneumonitis, according to a panel of pulmonary experts.
"It’s not always necessary to refer patients to academic centers where the specialists are," said Dr. Karen Patterson, who moderated the panel at the annual meeting of the American College of Chest Physicians. "That’s not always easy for patients, since those centers are often far away from where they live."
The key to accurate diagnosis is taking a thorough clinical history. Sometimes, that means asking family members the same questions asked of the patient, since not everyone recalls the same information, said Dr. Patterson of the Penn Lung Center at the University of Pennsylvania, Philadelphia.
Hypersensitivity pneumonitis is antigen driven, and lymphocytosis is a hallmark, Dr. Patterson said.
The allergens associated with the condition typically come from birds, but apparently not from chickens, according to panelist Dr. Kevin Brown of National Jewish Health in Denver.
Other antigens to ask about include bird products such as down bedding as well as mold and various industrial antigens.
Pulmonary and systemic symptoms can vary in intensity with each patient, Dr. Patterson said. When classifying the disease, it is important to distinguish between fibrotic and nonfibrotic disease. "Fibrotic disease is difficult to diagnose, and is associated with [poorer] outcomes," she said.
Patients present with dyspnea, hypoxemia, and cough as well as systemic manifestations such as fever, myalgia, weight loss, and fatigue.
CT findings are usually more thorough than radiography, said Dr. Patterson, who added that biopsy is necessary on rare occasions.
"Be sure to get all three lobes of the affected lung"; otherwise there will not be enough information to accurately assess the disease, she added.
"Antigen avoidance is the best management of hypersensitivity pneumonitis," according to Dr. Mary Strek of the University of Chicago. "Patients do best when you’ve accurately identified the antigen, and then removed it, although this is not always easy."
Treatment includes corticosteroids, and in some cases, immunosuppressive therapies.