Why Interstitial Lung Disease Diagnosis is Often Delayed

Briana DiSilvio, MD

Because diagnosis of an interstitial lung disease (ILD) is often delayed or mistakenly treated as another condition, a committee of expert pulmonologists and primary care physicians (PCPs) recently addressed the key contributors that lead to delays in ILD diagnosis.

"Interstitial lung disease commonly presents in the same manner as many other chronic lung and cardiac conditions," Briana DiSilvio, MD, Pulmonologist, Allegheny Health Network (AHN) explained in a written interview with HCPLive. "Unfortunately, this contributes to the frequent delay in diagnosis of ILD, with some patients having been misdiagnosed for years."

The white paper was released by the committee through combined efforts from the American College of Chest Physicians (CHEST) and Three Lakes Foundation, to share expert guidance for the initiative, Bridging Specialties: Timely Diagnosis for ILD Patients.

While there's no straightforward list of factors to uniformly amend this barrier, an analysis of surveys completed by PCPs demonstrated key behaviors that could contribute to the multifactorial issues.

The survey assessed typical treatment approaches to a patient presenting with non-specific symptoms in a primary care setting, and also aimed to gauge knowledge and perception around a diagnosis of pulmonary fibrosis (PF) or idiopathic pulmonary fibrosis (IPF).

The data revealed that when faced with a patient in this scenario, they are more likely to be evaluated for cardiac conditions, chronic obstructive pulmonary disease (COPD), or asthma than ILD or IPF, even when the patient's non-specific symptoms could be considered early indicators of the diseases.

Additionally, when a patient is already on inhaled therapy for a pulmonary condition, the evaluation approach shifts to therapy modulation instead of symptom evaluation for a considerable minority of PCPs (39%). According to feedback from pulmonologists, this practice doesn't account for the possibility of an initial misdiagnosis and could contribute to the delays seen in ILD diagnosis.

When it comes to imaging, the high-resolution computed tomography (HRCT) needed for detecting ILD isn't utilized frequently. When treating a patient with a chest radiograph that revealed lower lobe opacity, 38% of PCPs don't follow with an order for HRCT. For patients with inspiratory crackles or another abnormal pulmomary exam half of the PCPs reported they proceed with a HRCT examination.

Further insight on differentiating the presentations of interstitial lung diseases was provided by expert Briana DiSilvio, MD, Allegheny Health Network (AHN), in an interview with HCPLive. DiSilvio has extensive experience treating patients as a specialist in pulmonary and critical care. She has a clinical interest in pulmonary fibrosis and sarcoidosis, but her expertise extends to chronic lung conditions, pleural disease, and respiratory infections.

HCPLive: What are the varying presentations of ILD in patients and what are the main impacts on quality of life?

DiSilvio: The most common symptoms are shortness of breath, persistent cough, exercise intolerance, exhaustion and weakness. When ILDs are associated with underlying autoimmune conditions, patients may also experience joint pains, morning stiffness, rashes, skin thickening, color changes in the hands, muscle pain/weakness, dry mouth and/or dry eyes.

On occasion, ILDs are discovered incidentally when chest or abdominal imaging is performed for other reasons. Chest x-rays may reveal pulmonary infiltrates, reticulation (abnormal linear patterns), or nodules. CT chests can show linear, dense nodular, or hazy opacities, air trapping, cystic changes, and/or bronchial wall thickening. When fibrosis is present, it manifests as architectural distortion, traction bronchiectasis, thickening of the lung interstitium, and occasionally honeycomb pattern.

Interstitial lung disease, especially when untreated and in late stages of progression, is well known to impact health related quality of life. Chronic dyspnea, cough, and reduced exercise capacity can become disabling. Many patients become dependent on oxygen supplementation which further limits their ambulation and ability to comfortably engage in routine activities of daily living.

Lung function decline is unpredictable and can be unexpectedly accelerated by an acute ILD exacerbation which usually requires hospitalization for treatment. Patient’s rarely recover to baseline after an acute flare. Non-respiratory symptoms are prevalent in ILD and include depression, anxiety, weight loss, poor appetite, and low energy levels. This high burden of disease is reflected by a significant loss of functional years of life and increased mortality rates.