USMLE Step 2 Quiz: Obstructive And Restrictive Lung Disease

What this quiz covers

This quiz focuses on Obstructive And Restrictive Lung Disease, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 2.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Obstructive defect consistent with COPD physiology (correct answer)
2. Restrictive defect consistent with pulmonary fibrosis
3. Normal spirometry inconsistent with lung disease
4. Upper airway obstruction consistent with vocal cord dysfunction

Explanation: This question tests USMLE Step 2 CK knowledge of obstructive and restrictive lung disease, focusing on diagnosis and management. Pulmonary function tests differentiate between obstructive (e.g., COPD, asthma) and restrictive diseases (e.g., pulmonary fibrosis, interstitial lung disease) based on FEV1/FVC ratios. In this vignette, the patient's history and spirometry results suggest COPD. The obstructive defect consistent with COPD physiology is appropriate due to the low FEV1/FVC ratio. Choice A is correct because it aligns with GOLD spirometric criteria for COPD. Choice B is incorrect because it fails to consider that restrictive defects have normal or high FEV1/FVC. Teach students to assess spirometry results carefully and consider patient history, such as smoking status or occupational exposures, when forming a differential diagnosis. Encourage familiarity with guidelines for common pulmonary conditions.

Question 2

1. Order ANA and other connective tissue serologies (correct answer)
2. Start LABA/LAMA inhaler for airway obstruction
3. Diagnose asthma based on intermittent dyspnea alone
4. Treat empirically with antibiotics for bronchitis

Explanation: This question tests USMLE Step 2 CK knowledge of obstructive and restrictive lung disease, focusing on diagnosis and management. Pulmonary function tests differentiate between obstructive (e.g., COPD, asthma) and restrictive diseases (e.g., pulmonary fibrosis, interstitial lung disease) based on FEV1/FVC ratios. In this vignette, the patient's history and spirometry results suggest scleroderma-related ILD. The ANA and other connective tissue serologies are appropriate due to symptoms suggesting autoimmune etiology. Choice A is correct because it aligns with ATS/ERS guidelines for ILD workup in suspected connective tissue disease. Choice B is incorrect because it fails to consider the restrictive pattern inconsistent with obstruction. Teach students to assess spirometry results carefully and consider patient history, such as smoking status or occupational exposures, when forming a differential diagnosis. Encourage familiarity with guidelines for common pulmonary conditions.

Question 3

1. Occupational and home exposures, including birds and mold (correct answer)
2. Recent travel to assess for malaria exposure
3. Childhood vaccination status for pertussis immunity
4. Daily caffeine intake to assess palpitations cause

Explanation: This question tests USMLE Step 2 CK knowledge of obstructive and restrictive lung disease, focusing on diagnosis and management. Pulmonary function tests differentiate between obstructive (e.g., COPD, asthma) and restrictive diseases (e.g., pulmonary fibrosis, interstitial lung disease) based on FEV1/FVC ratios. In this vignette, the patient's history and spirometry results suggest interstitial lung disease. The occupational and home exposures, including birds and mold, are appropriate due to their role in identifying hypersensitivity pneumonitis. Choice A is correct because it aligns with ATS guidelines for ILD history-taking. Choice B is incorrect because it fails to consider that travel history is less relevant for chronic ILD. Teach students to assess spirometry results carefully and consider patient history, such as smoking status or occupational exposures, when forming a differential diagnosis. Encourage familiarity with guidelines for common pulmonary conditions.

Question 4

1. Cystic fibrosis
2. Alpha-1 antitrypsin deficiency (correct answer)
3. Common variable immunodeficiency
4. Kartagener syndrome

Explanation: The development of emphysema in a young non-smoker, particularly with a basilar-predominant, panacinar pattern, is highly suggestive of alpha-1 antitrypsin (AAT) deficiency. AAT is a protein that protects the lungs from damage by neutrophil elastase. Its deficiency leads to unchecked elastin destruction and early-onset emphysema. The associated liver enzyme elevation is due to the accumulation of abnormal AAT protein in hepatocytes, which can lead to cirrhosis.

Question 5

1. Pure obstructive defect
2. Pure restrictive defect
3. Mixed obstructive and restrictive defect (correct answer)
4. Normal pulmonary function

Explanation: This patient has risk factors for both obstructive disease (smoking leading to COPD) and restrictive disease (rheumatoid arthritis can cause interstitial lung disease). The PFTs confirm this. The FEV1/FVC ratio < 0.70 indicates an obstructive defect. The total lung capacity (TLC) < 80% of predicted indicates a restrictive defect. The presence of both defines a mixed obstructive and restrictive pattern.

Question 6

1. Bacterial pneumonia
2. Allergic bronchopulmonary aspergillosis (ABPA) (correct answer)
3. Churg-Strauss syndrome (EGPA)
4. Cystic fibrosis

Explanation: Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction to Aspergillus fumigatus that occurs almost exclusively in patients with asthma or cystic fibrosis. The clinical picture includes poorly controlled asthma, production of brownish mucus plugs, fleeting pulmonary infiltrates, central bronchiectasis, peripheral eosinophilia, and markedly elevated total serum IgE levels. This patient's presentation is classic for ABPA.

Question 7

1. A short-acting beta-agonist used 15 minutes before exercise (correct answer)
2. A daily low-dose inhaled corticosteroid
3. An oral leukotriene receptor antagonist taken daily
4. Complete avoidance of soccer and other strenuous activities

Explanation: This patient's symptoms are classic for exercise-induced bronchoconstriction (EIB). The first-line treatment for EIB is the prophylactic use of a short-acting beta-agonist (SABA), such as albuterol, taken 10-20 minutes before exercise. This prevents the bronchoconstriction triggered by exertion. Daily controller medications like ICS or leukotriene antagonists are considered if symptoms persist despite pre-treatment with a SABA or if the patient also has persistent asthma.

Question 8

1. Asthma
2. Chronic obstructive pulmonary disease (correct answer)
3. Idiopathic pulmonary fibrosis
4. Sarcoidosis

Explanation: The patient's clinical presentation (long-term smoker, chronic cough, dyspnea) and pulmonary function tests are classic for chronic obstructive pulmonary disease (COPD). The key finding is an FEV1/FVC ratio of < 0.70 (here it is 0.50), which defines an obstructive pattern. The increased total lung capacity is consistent with air trapping, and the decreased DLCO reflects emphysematous destruction of the alveolar-capillary membrane.

Question 9

1. Obstructive lung disease
2. Interstitial lung disease (correct answer)
3. Neuromuscular weakness
4. Vascular lung disease

Explanation: The patient's pulmonary function tests demonstrate a restrictive pattern, characterized by a reduced FVC and TLC with a normal or increased FEV1/FVC ratio. The significantly reduced DLCO points towards a parenchymal cause of restriction, such as interstitial lung disease (e.g., idiopathic pulmonary fibrosis), which damages the alveolar-capillary interface. Neuromuscular weakness would cause a restrictive pattern but typically with a normal DLCO.

Question 10

1. Initiation of a long-acting beta-agonist
2. A dose of inhaled corticosteroid
3. Administration of systemic corticosteroids (correct answer)
4. Oral montelukast

Explanation: This patient is experiencing a moderate-to-severe asthma exacerbation. The cornerstone of management for such exacerbations, in addition to supplemental oxygen and repetitive short-acting beta-agonists (SABAs), is early administration of systemic corticosteroids (e.g., prednisone, methylprednisolone). Systemic corticosteroids reduce airway inflammation and are crucial for resolving the exacerbation and preventing relapse. Inhaled corticosteroids and other long-term controllers are not effective for acute management.

Question 11

1. Add a daily low-dose inhaled corticosteroid (correct answer)
2. Add a long-acting beta-agonist inhaler
3. Schedule allergy testing
4. Continue with as-needed albuterol only

Explanation: This patient's symptoms (use of SABA >2 days/week but not daily, and 1-3 nocturnal awakenings/month) classify her as having mild persistent asthma. The recommended next step in management (Step 2 care) is to add a daily controller medication. The preferred controller for mild persistent asthma is a low-dose inhaled corticosteroid (ICS). Adding a LABA without an ICS is contraindicated in asthma.

Question 12

1. An increase in FEV1 by 100 mL and 8%
2. An increase in FEV1 by 250 mL and 15% (correct answer)
3. No significant change in FEV1 or FVC
4. A decrease in total lung capacity (TLC)

Explanation: A significant response to bronchodilators is a key feature that helps distinguish asthma from COPD, although some COPD patients have a reversible component. A positive bronchodilator response is defined as an increase in either FEV1 or FVC by at least 12% AND at least 200 mL from the baseline measurement. An increase of 250 mL and 15% clearly meets this criterion and points towards a significant reversible component, which is more characteristic of asthma.

Question 13

1. Decreased FEV1/FVC, increased TLC, normal DLCO
2. Normal FEV1/FVC, decreased TLC, decreased DLCO
3. Normal FEV1/FVC, decreased TLC, normal DLCO (correct answer)
4. Decreased FEV1/FVC, normal TLC, decreased DLCO

Explanation: Myasthenia gravis is a neuromuscular disorder that causes weakness of the respiratory muscles, including the diaphragm. This weakness leads to an extrinsic restrictive lung disease pattern. The PFT findings will show a reduced total lung capacity (TLC) and forced vital capacity (FVC), with a preserved or normal FEV1/FVC ratio. Because the lung parenchyma itself is unaffected, the diffusing capacity for carbon monoxide (DLCO) is expected to be normal.

Question 14

1. Tuberculosis
2. Lymphoma
3. Sarcoidosis (correct answer)
4. Hypersensitivity pneumonitis

Explanation: This patient's presentation of respiratory symptoms, bilateral hilar adenopathy, erythema nodosum (tender nodules on shins), and demographic profile is classic for sarcoidosis. The restrictive pattern on PFTs is also consistent with parenchymal involvement, even if not yet prominent on chest x-ray. While lymphoma and TB can present with hilar adenopathy, the constellation of findings, especially erythema nodosum, makes sarcoidosis the most probable diagnosis.

Question 15

1. Chest x-ray
2. High-resolution computed tomography (HRCT) (correct answer)
3. Ventilation-perfusion (V/Q) scan
4. Pulmonary angiography

Explanation: The patient's history of chronic productive cough with large sputum volumes and recurrent infections is highly suggestive of bronchiectasis, which is the permanent and abnormal dilation of the bronchi. While a chest x-ray may show some findings like 'tram tracks', the diagnostic imaging modality of choice is a high-resolution computed tomography (HRCT) scan of the chest. HRCT can directly visualize the dilated airways and thickened bronchial walls characteristic of the disease.

Question 16

1. Oral candidiasis (correct answer)
2. Hepatic toxicity
3. Renal insufficiency
4. Pulmonary embolism

Explanation: Fluticasone is an inhaled corticosteroid (ICS). The most common local side effects of ICS therapy are oropharyngeal candidiasis (thrush) and dysphonia (hoarseness). These risks can be minimized by using a spacer device and rinsing the mouth after use. While high-dose systemic corticosteroids are associated with osteoporosis, the risk from standard-dose inhaled corticosteroids is much lower, though still a consideration. Hepatic and renal toxicity are not typical side effects. Oral candidiasis is a very common and direct side effect.

Question 17

1. Idiopathic pulmonary fibrosis
2. Asbestosis
3. Morbid obesity (correct answer)
4. Sarcoidosis with parenchymal involvement

Explanation: Restrictive lung disease can be caused by intrinsic (parenchymal) disease or extrinsic causes (chest wall, pleura, neuromuscular weakness). DLCO helps differentiate these. Intrinsic diseases like pulmonary fibrosis, asbestosis, and sarcoidosis damage the alveolar-capillary membrane, leading to a low DLCO. Extrinsic causes, such as morbid obesity, kyphoscoliosis, or neuromuscular diseases, restrict lung expansion but leave the lung parenchyma intact, resulting in a restrictive pattern on spirometry with a normal DLCO.

Question 18

1. COPD with emphysema
2. Hypersensitivity pneumonitis
3. Sarcoidosis
4. Idiopathic pulmonary fibrosis (correct answer)

Explanation: The combination of a restrictive pattern on PFTs, reduced DLCO, and classic radiologic findings of a usual interstitial pneumonia (UIP) pattern (bibasilar, subpleural honeycombing and traction bronchiectasis) in an older adult is highly specific for idiopathic pulmonary fibrosis (IPF). While smoking is a risk factor for both COPD and IPF, the PFT and imaging findings here are characteristic of IPF.

Question 19

1. Pulmonary rehabilitation
2. Continuous long-term oxygen therapy (correct answer)
3. Daily azithromycin
4. Lung volume reduction surgery

Explanation: Long-term oxygen therapy is one of the few interventions in COPD that has been proven to improve survival. The criteria for initiating long-term oxygen therapy include a PaO2 ≤ 55 mmHg or an O2 saturation ≤ 88% on room air at rest, or a PaO2 between 56-59 mmHg in the presence of cor pulmonale or polycythemia (hematocrit > 55%). This patient's PaO2 of 54 mmHg meets the criteria.

Question 20

1. A long-acting bronchodilator (LABA or LAMA) (correct answer)
2. An inhaled corticosteroid (ICS)
3. Roflumilast
4. Daily oral prednisone

Explanation: This patient has GOLD Grade 2, Group B COPD (few exacerbations but significant symptoms, CAT ≥ 10). The recommended initial maintenance therapy for Group B patients is a long-acting bronchodilator, either a long-acting beta-agonist (LABA) or a long-acting muscarinic antagonist (LAMA). An ICS is typically reserved for patients with frequent exacerbations (Group D) or those with concomitant asthma features.