Patient will present as → a 55-year-old female who is a current smoker presents with a 9-month history of respiratory symptoms, including dyspnea on exertion, thoracic pain, and dry cough, which were preceded by a pulmonary infection. On auscultation, you hear inspiratory crackles. Pulmonary function tests (PFTs) show a decrease in total lung capacity, decreased forced vital capacity (FVC), and decreased forced expiratory volume in 1 second (FEV1). Chest CT demonstrates diffuse patchy fibrosis with pleural-based honeycombing.
Chronic progressive lung disorder characterized by increasing scarring, which ultimately reduces the capacity of the lungs; etiology unknown
- Idiopathic pulmonary fibrosis is the most common of all interstitial lung diseases
- In order to be considered "idiopathic" you must be sure to rule out other common causes such as drugs, and environmental or occupational exposures
Common "non-idiopathic" causes of pulmonary fibrosis which must be ruled out:
- Cigarette smoking
- Certain viral infections
- Exposure to environmental pollutants, including silica and hard metal dusts, bacteria and animal proteins, and gases and fumes
- The use of certain medicines (methotrexate, amiodarone, nitrofurantoin, rituximab, bleomycin, and cyclophosphamide)
- Genetics
- Radiation treatment
- Gastroesophageal reflux disease (GERD)
CXR shows fibrosis
- CT chest: diffuse patchy fibrosis with pleural-based honeycombing
- PFTs will demonstrate a restrictive pattern - opposite of what you would see with asthma
- Lung volume decreases in restrictive lung disease and the FEV1/FVC ratio is greater than 80% (increased) due to a significant decrease in forced vital capacity (FVC)
Chest CT showing classic "honeycombing"
Treatment may include antifibrotic drugs (pirfenidone or nintedanib), oxygen therapy, and eventually lung transplant
- Most patients deteriorate and the median survival is about 3 years from diagnosis
 Osmosis |
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Restrictive lung diseases can be caused by either poor breathing mechanics, a result of conditions like myasthenia gravis, obesity, and scoliosis. They can also result from interstitial lung disease such as pneumoconioses or ARDS. Lung volume decreases in restrictive lung disease and the FEV1/FVC ratio is greater than 80% due to a significant decrease in forced vital capacity (FVC). FEV1 is the forced expiratory volume in 1 second or the volume of air that can forcibly be blown out in one second, after full inspiration. FVC is the forced vital capacity or the volume of air that can forcibly be blown out after full inspiration. Both these values can be measured by spirometry. The ratio between the FEV1 and FVC can help distinguish between restrictive and obstructive lung diseases. A ratio greater than 80% suggests a restrictive condition.
Play Video + QuizObstructive lung disease
Obstructive lung disease is characterized by airway obstruction and it is associated with inflammation of the airways and problems exhaling. Types of obstructive lung disease are asthma, bronchiectasis, bronchitis, and COPD. Obstructive lung disease results in air trapping in the lungs which expands the lung volume over time. A decrease in FEV1/FVC ratio suggests an obstructive condition.
Play Video + QuizRestrictive vs. Obstructive Lung Diseases
Lung diseases can be classified as either restrictive or obstructive. Restrictive lung diseases cause a decrease in lung volume. Obstructive lung diseases trap air in the lungs and therefore increase lung volume.
Play Video + QuizQuestion 1 |
Early inspiratory crackles Hint: Late, not early, inspiratory crackles are associated with interstitial lung disease. | |
Progressive dyspnea on exertion | |
Productive cough with copious sputum Hint: A productive cough of copious amounts of sputum is most typical of a patient with chronic bronchitis. | |
Decreased breath sounds with hyperresonant percussion Hint: Physical examination findings of decreased breath sounds with hyperresonant percussion is consistent with a diagnosis of chronic obstructive lung disease. |
Question 2 |
COPD Hint: COPD appears as hyperinflation with flattening of the diaphragm on chest radiograph | |
Tuberculosis Hint: Tuberculosis presents with pulmonary infiltrates on chest radiograph most often apical; cavitations may be seen with progressive primary tuberculosis. | |
Bronchiectasis Hint: Chest x-ray in bronchiectasis shows dilated and thickened bronchi that appear as ring-like markings. | |
Pulmonary fibrosis |
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References: Merck Manual · UpToDate