Respiratory Diseases Practice Questions

Q: A previously well 1-year-old infant has had a runny nose and has been sneezing and coughing for 2 days. Two other members of the family had similar symptoms. Four hours ago, his cough became much worse. On physical examination, he is in moderate respiratory distress with tachypnea and nasal flaring. Upon auscultation, he has easily audible wheezing with scattered crackles bilaterally. His arterial blood gas on room air revealed a pH of 7.46, a PaCO2 of 34 mm Hg, and a PaO2 of 75 mm Hg. His chest radiograph shows bilateral hyperinflation with flattened diaphragms and peribronchial thickening, without focal consolidation. Which of the following is the appropriate next course of action?

Monitoring oxygenation and fluid status. ***Monitoring oxygenation and fluid status*** - This 1-year-old infant presents with classic **bronchiolitis** (likely **RSV**) given the viral **upper respiratory prodrome**, family clustering, and bilateral **wheeze with crackles**. - **AAP guidelines** recommend supportive care with **oxygen monitoring** and **fluid management** as first-line treatment, avoiding unnecessary interventions in mild-moderate cases. *Inhaled epinephrine and a single dose of steroids* - **Epinephrine** is indicated for **croup** (barking cough, stridor), not bronchiolitis with bilateral wheeze and crackles. - **Steroids** have no proven benefit in **bronchiolitis** and are not recommended by current pediatric guidelines. *Acute-acting bronchodilators and a short course of oral steroids* - **Bronchodilators** (albuterol/salbutamol) show minimal benefit in **bronchiolitis** and are not routinely recommended in infants under 2 years. - **Oral steroids** are ineffective in viral **bronchiolitis** and may increase risk of secondary bacterial infections. *Emergent intubation, mechanical ventilation, and antibiotics* - Patient has **moderate respiratory distress** but **normal pH** (7.46) and **adequate oxygenation** (PaO2 75 mmHg), not requiring immediate intubation. - **Antibiotics** are not indicated as this is a **viral illness** (bronchiolitis) without evidence of bacterial superinfection.

Q: A 7.5-year-old girl presents with a non-productive cough and mild stridor for 3 months. Her condition was improving, but she suddenly developed wheeze, productive cough, and mild fever. Chest X-ray shows hyperlucency, and pulmonary function tests reveal an obstructive pattern. What is the most probable diagnosis?

Bronchiolitis obliterans. **Explanation:** **Bronchiolitis Obliterans (BO)** is a chronic obstructive lung disease resulting from an insult to the lower respiratory tract, leading to inflammation and fibrosis of the small airways (bronchioles). 1. **Why it is correct:** The clinical presentation follows a classic pattern: an initial acute insult (often viral like Adenovirus or Mycoplasma) followed by a period of relative improvement, and then the development of chronic symptoms like **non-productive cough, persistent wheeze, and stridor**. The **hyperlucency** on Chest X-ray (due to air trapping) and the **obstructive pattern** on PFTs are hallmark findings of BO in children. 2. **Why other options are incorrect:** * **Hemosiderosis:** Presents with a triad of hemoptysis, iron deficiency anemia, and diffuse parenchymal infiltrates (not hyperlucency). * **Pulmonary Alveolar Microlithiasis:** A rare genetic disorder characterized by "sand-like" calcifications (microliths) within alveoli. X-ray shows a classic "sandstorm" appearance, not hyperlucency. * **Follicular Bronchitis:** Usually associated with immunodeficiency or connective tissue disorders; it typically presents with a nodular pattern on CT rather than isolated hyperlucency and obstructive PFTs. **Clinical Pearls for NEET-PG:** * **Post-infectious BO:** The most common cause in children is **Adenovirus** (Types 3, 7, and 21). * **Radiology:** Look for the **"Mosaic attenuation"** pattern on HRCT, which is the gold standard for diagnosis. * **Swyer-James-MacLeod Syndrome:** A sequela of post-infectious BO where one lung or lobe remains hyperlucent and small due to obliterated vascularity and air trapping.

Q: All of the following are used in the acute attack of asthma in a 4-year-old child, except:

Sedatives. In the management of acute asthma, the primary goal is to relieve airway obstruction and reduce inflammation. **Why Sedatives are Contraindicated (Correct Answer):** Sedatives (such as benzodiazepines or promethazine) are strictly contraindicated in acute asthma. They cause **respiratory center depression**, which can lead to hypoventilation, hypercapnia, and respiratory failure. In a child struggling to breathe, anxiety is often a physiological sign of hypoxia; suppressing this drive can be fatal. **Explanation of Other Options:** * **Salbutamol (Short-Acting Beta-2 Agonist):** This is the **first-line treatment** (Gold Standard) for acute attacks. It acts rapidly to cause bronchodilation by relaxing airway smooth muscle. * **Corticosteroids:** These are essential in acute management to reduce airway inflammation and edema. They prevent late-phase reactions and reduce the risk of relapse. Systemic steroids (oral or IV) are typically used in acute exacerbations. * **Theophylline:** While no longer first-line due to a narrow therapeutic index and side effects, intravenous Aminophylline/Theophylline can be used as an **add-on therapy** in severe refractory asthma (Status Asthmaticus) that does not respond to initial bronchodilators. **Clinical Pearls for NEET-PG:** * **Drug of Choice (Acute):** Inhaled Salbutamol (via MDI with spacer or nebulization). * **Most sensitive indicator of severity:** Use of accessory muscles and inability to speak in full sentences. * **Silent Chest:** A grave clinical sign indicating minimal air entry; it is a medical emergency. * **Magnesium Sulfate:** Used intravenously in severe cases for its smooth muscle relaxant properties.

Q: A 3-year-old, well-immunized male child presents with sore throat, fever, noisy breathing, and inability to swallow for the past four hours. Examination reveals a toxic, tachypneic child with inspiratory stridor, suprasternal, supraclavicular, and intercostal retractions during inspiration. What is the most likely diagnosis?

Acute Epiglottitis. **Explanation:** The clinical presentation of a **toxic-looking** child with a rapid onset of high fever, sore throat, **drooling (inability to swallow)**, and inspiratory stridor is classic for **Acute Epiglottitis**. This is a life-threatening pediatric emergency involving inflammation of the supraglottic structures. The "4 Ds" (Drooling, Dysphagia, Distress, and Dysphonia) are hallmark signs. Despite being well-immunized (which reduces the risk of *H. influenzae* type b), other pathogens like *Streptococcus pyogenes* or *Staphylococcus aureus* can still cause the condition. **Why other options are incorrect:** * **Acute Laryngotracheobronchitis (Croup):** Typically presents with a "barking" cough, hoarseness, and a slower prodrome of URI symptoms. The child is usually not "toxic" or drooling. * **Diphtheria:** Characterized by a slow onset, low-grade fever, and a thick, grey, adherent **pseudomembrane** on the tonsils/pharynx. It does not typically cause the acute, fulminant respiratory distress seen here. * **Bronchopneumonia:** Presents with cough, rales/crepitations, and expiratory wheezing rather than inspiratory stridor. Stridor indicates an upper airway obstruction. **NEET-PG High-Yield Pearls:** * **X-ray Finding:** Lateral neck X-ray shows the **"Thumb sign"** (swollen epiglottis). * **Management:** The priority is **airway stabilization** (intubation) in a controlled environment (OR). Do not examine the throat with a tongue depressor, as it may trigger fatal laryngospasm. * **Positioning:** Children often assume the **"Tripod position"** (leaning forward on hands) to maximize airway diameter.

Q: What is the most likely etiology in a 10-month-old child with a 7-day history of high-grade fever, exhibiting the following X-ray findings, and not responding to ceftriaxone?

Staphylococcus aureus. ***Staphylococcus aureus*** - Characteristic X-ray findings in infants include **pneumatoceles**, **empyema**, and **pyopneumothorax**, which are pathognomonic for staphylococcal pneumonia. - Failure to respond to **ceftriaxone** suggests **MRSA**, as ceftriaxone does not provide adequate coverage against methicillin-resistant strains. *Streptococcus pneumoniae* - Typically responds well to **ceftriaxone** therapy, making this unlikely given the treatment failure described. - Usually presents with **lobar consolidation** on chest X-ray without the characteristic cavitary lesions or pneumatoceles seen with staph infections. *Mycoplasma* - Predominantly affects **school-age children** and adolescents, not typically seen in 10-month-old infants. - Presents with **atypical pneumonia** symptoms including gradual onset, dry cough, and bilateral interstitial infiltrates rather than high-grade fever and cavitary lesions. *Respiratory Syncytial Virus* - Causes **bronchiolitis** with hyperinflation and peribronchial thickening on chest X-ray, not lobar pneumonia with cavitary changes. - Typically presents with **wheezing**, **rhinorrhea**, and **cough** rather than high-grade fever and pneumonic consolidation.

Q: An infant has a positive newborn screening test for cystic fibrosis. What cutoff of sweat chloride concentration confirms cystic fibrosis?

Sweat chloride > 60 mEq/L. **Explanation:** The diagnosis of Cystic Fibrosis (CF) is primarily confirmed using the **Quantitative Pilocarpine Iontophoresis Test (QPIT)**, commonly known as the Sweat Chloride Test. In CF, a defect in the CFTR protein prevents the reabsorption of chloride in the sweat ducts, leading to abnormally high concentrations of salt in the sweat. **1. Why Option D is Correct:** According to the current clinical guidelines (Cystic Fibrosis Foundation), a **sweat chloride concentration of ≥ 60 mmol/L (or mEq/L)** on two separate occasions is considered diagnostic for Cystic Fibrosis in individuals of all ages, including infants identified via newborn screening. **2. Analysis of Incorrect Options:** * **Option A (< 30 mEq/L):** This is considered the **normal** range. CF is highly unlikely at this level. * **Option B & C (30–59 mEq/L):** This range is classified as **Intermediate (Borderline)**. It is not diagnostic of CF but requires further evaluation, such as repeat sweat testing or CFTR genetic mutation analysis (extended sequencing). **3. High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard:** Sweat Chloride Test (QPIT) remains the gold standard for diagnosis. * **Newborn Screening:** Usually involves testing for **Immunoreactive Trypsinogen (IRT)**. If elevated, it is followed by DNA testing or sweat testing. * **False Positives:** Conditions like Adrenal Insufficiency, Ectodermal Dysplasia, Nephrogenic Diabetes Insipidus, and Malnutrition can occasionally cause elevated sweat chloride. * **Genetics:** CF is an Autosomal Recessive disorder; the most common mutation is **ΔF508** on Chromosome 7. * **Clinical Triad:** Chronic sinopulmonary disease, pancreatic insufficiency (steatorrhea), and high sweat chloride levels.

Question 1

A previously well 1-year-old infant has had a runny nose and has been sneezing and coughing for 2 days. Two other members of the family had similar symptoms. Four hours ago, his cough became much worse. On physical examination, he is in moderate respiratory distress with tachypnea and nasal flaring. Upon auscultation, he has easily audible wheezing with scattered crackles bilaterally. His arterial blood gas on room air revealed a pH of 7.46, a PaCO2 of 34 mm Hg, and a PaO2 of 75 mm Hg. His chest radiograph shows bilateral hyperinflation with flattened diaphragms and peribronchial thickening, without focal consolidation. Which of the following is the appropriate next course of action?

Accepted Answer

Monitoring oxygenation and fluid status

Answer

Inhaled epinephrine and a single dose of steroids

Answer

Acute-acting bronchodilators and a short course of oral steroids

Answer

Emergent intubation, mechanical ventilation, and antibiotics

Question 2

A 4-month-old infant presents with cough and a respiratory rate greater than 60/min, without retractions. What is the appropriate management according to the Integrated Management of Childhood Illness (IMNCI) protocol?

Accepted Answer

Administer oral antibiotic, explain danger signs, and arrange for follow-up.

Answer

Administer IM antibiotic and refer urgently.

Answer

Explain danger signs and arrange for follow-up.

Answer

Administer IM antibiotic and hospitalize.

Question 3

A 7.5-year-old girl presents with a non-productive cough and mild stridor for 3 months. Her condition was improving, but she suddenly developed wheeze, productive cough, and mild fever. Chest X-ray shows hyperlucency, and pulmonary function tests reveal an obstructive pattern. What is the most probable diagnosis?

Accepted Answer

Bronchiolitis obliterans

Answer

Hemosiderosis

Answer

Pulmonary alveolar microlithiasis

Answer

Follicular bronchitis

Question 4

All of the following are used in the acute attack of asthma in a 4-year-old child, except:

Accepted Answer

Sedatives

Answer

Theophylline

Answer

Corticosteroids

Answer

Salbutamol

Question 5

A 4-month-old infant presents with cough and a respiratory rate greater than 60/min, with no chest retractions. What is the appropriate management according to the Integrated Management of Childhood Illness (IMNCI) protocol?

Accepted Answer

Administer oral antibiotics, explain danger signs, and schedule a follow-up.

Answer

Administer intramuscular antibiotics and refer urgently.

Answer

Explain danger signs and schedule a follow-up.

Answer

Administer intramuscular antibiotics and hospitalize.

Question 6

A 3-year-old, well-immunized male child presents with sore throat, fever, noisy breathing, and inability to swallow for the past four hours. Examination reveals a toxic, tachypneic child with inspiratory stridor, suprasternal, supraclavicular, and intercostal retractions during inspiration. What is the most likely diagnosis?

Accepted Answer

Acute Epiglottitis

Answer

Acute Laryngotracheobronchitis

Answer

Diphtheria

Answer

Bronchopneumonia

Question 7

A 14-year-old boy presented with chronic diarrhea and weight loss. History reveals that he has repeated attacks of respiratory tract infections with Pseudomonas aeruginosa. His younger brother died from a severe respiratory infection at the age of 7. Which of the following agents is most likely to improve this patient's condition?

Accepted Answer

Pancreatic lipase

Answer

Octreotide

Answer

Metronidazole

Answer

Loperamide

Question 8

What is the MOST suitable management for a 2-year-old child presenting with cough for 5 days? On examination, the respiratory rate is 40/minute. The child is well-nourished, active, and feeding well.

Accepted Answer

Advise mother to provide home care.

Answer

Start cotrimoxazole in age-appropriate doses.

Answer

Start with the first dose of intramuscular ampicillin.

Answer

None of the above.

Question 9

What is the most likely etiology in a 10-month-old child with a 7-day history of high-grade fever, exhibiting the following X-ray findings, and not responding to ceftriaxone?

Accepted Answer

Staphylococcus aureus

Answer

Streptococcus pneumoniae

Answer

Mycoplasma

Answer

Respiratory Syncytial Virus

Question 10

An infant has a positive newborn screening test for cystic fibrosis. What cutoff of sweat chloride concentration confirms cystic fibrosis?

Accepted Answer

Sweat chloride > 60 mEq/L

Answer

Sweat chloride > 30 mEq/L

Answer

Sweat chloride > 40 mEq/L

Answer

Sweat chloride > 50 mEq/L

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

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