Respiratory Diseases — MCQs
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A 5-year-old child suddenly develops stridor. Which one of the following would be the most likely diagnosis?
Hyaline membrane disease presents as?
A couple presents for work-up of infertility after 5 years of unprotected intercourse. The wife denies any medical problems and notes regular menstrual cycles. The husband reports a history of chronic sinusitis and lower respiratory tract infections. Physical examination of the woman is unremarkable. Examination of the man reveals dextrocardia. Further work-up of the husband will most likely reveal?
Infants with cystic fibrosis (CF) are likely to develop which of the following complications?
According to WHO guidelines, which of the following is NOT an indication for hospital admission in pneumonia?
Aerosolized ribavirin is used in the treatment of bronchiolitis with which causative organism?
Which of the following is seen in cystic fibrosis?
A child presents with recurrent sinusitis and repeated lung infections. Genetic testing shows a mutation in the CFTR gene. Which test is considered the gold standard to confirm the diagnosis?
A 4-month-old infant is brought to the emergency department with a respiratory rate of 66 breaths per minute, along with chest indrawing and nasal flaring. There are no other significant findings. What is the most likely diagnosis?
A 3-month-old child has a respiratory rate of 56/min with no chest indrawing and no danger signs. As per IMNCI what is the most appropriate diagnosis?
Respiratory Diseases Indian Medical PG Practice Questions and MCQs
Question 221: A 5-year-old child suddenly develops stridor. Which one of the following would be the most likely diagnosis?
- A. Laryngomalacia
- B. Acute laryngotracheobronchitis
- C. Foreign body aspiration (Correct Answer)
- D. Acute epiglottitis
Explanation: ### Explanation The key to answering this question lies in the word **"suddenly."** In a pediatric patient, the sudden onset of respiratory distress or stridor without preceding symptoms (like fever or cough) is a classic presentation of **Foreign Body Aspiration (FBA)**. #### Why Foreign Body Aspiration is Correct: FBA typically occurs in children aged 1–3 years but remains a critical diagnosis in older children. The hallmark is an **acute, "choking episode"** followed by sudden-onset stridor (if the object is in the upper airway) or localized wheezing (if in the lower airway). Unlike infectious causes, there is no prodrome of fever or upper respiratory infection. #### Why Other Options are Incorrect: * **Laryngomalacia:** This is the most common cause of *congenital* stridor. It typically presents in the first few weeks of life, is chronic, and is characterized by inspiratory stridor that worsens when the infant is supine or crying. It does not develop "suddenly" at age 5. * **Acute Laryngotracheobronchitis (Croup):** While common in children, it typically presents with a **prodrome** of runny nose and low-grade fever, followed by a characteristic "barking" cough and inspiratory stridor. It is rarely "sudden" in its initial onset. * **Acute Epiglottitis:** Although it has a rapid progression, it is usually accompanied by **high-grade fever**, drooling, and a "tripod position." The incidence has significantly decreased due to the HiB vaccine. #### NEET-PG High-Yield Pearls: * **Most common site for FBA:** Right main bronchus (due to it being wider, shorter, and more vertical). * **Gold Standard Investigation:** Rigid Bronchoscopy (both diagnostic and therapeutic). * **X-ray finding:** Often normal, but may show an "air-trapping" effect (obstructive emphysema) on expiration. * **Laryngomalacia:** Characterized by "omega-shaped" epiglottis on laryngoscopy.
Question 222: Hyaline membrane disease presents as?
- A. Pulmonary edema
- B. Heart failure
- C. Acute respiratory distress syndrome (Correct Answer)
- D. Pulmonary embolism
Explanation: **Explanation:** **Hyaline Membrane Disease (HMD)**, also known as **Infant Respiratory Distress Syndrome (IRDS)**, is primarily caused by a deficiency of pulmonary surfactant in premature neonates. **Why Option C is Correct:** Surfactant deficiency leads to increased surface tension within the alveoli, causing widespread atelectasis (alveolar collapse). This results in a ventilation-perfusion (V/Q) mismatch, decreased lung compliance, and severe hypoxia. Pathologically, this manifests as the formation of eosinophilic "hyaline membranes" (composed of fibrin and cellular debris) lining the alveoli. This clinical and pathological sequence is the neonatal equivalent of **Acute Respiratory Distress Syndrome (ARDS)**, characterized by acute onset respiratory failure and diffuse bilateral infiltrates. **Why Other Options are Incorrect:** * **A & B (Pulmonary Edema/Heart Failure):** While HMD can be complicated by a Patent Ductus Arteriosus (PDA) leading to heart failure, HMD itself is a primary parenchymal lung disease due to surfactant lack, not a primary cardiac or fluid overload issue. * **D (Pulmonary Embolism):** This is an obstructive vascular phenomenon extremely rare in neonates; HMD is a restrictive alveolar disease. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Prematurity (most common), Maternal Diabetes, Cesarean section without labor, and being the second-born twin. * **Chest X-ray Findings:** Characterized by a diffuse **"Ground Glass Appearance"** and **Air Bronchograms**. * **L/S Ratio:** A Lecithin/Sphingomyelin ratio of **<2:1** in amniotic fluid indicates fetal lung immaturity. * **Management:** Antenatal corticosteroids (Dexamethasone/Betamethasone) to the mother and exogenous surfactant replacement (e.g., Beractant) for the neonate.
Question 223: A couple presents for work-up of infertility after 5 years of unprotected intercourse. The wife denies any medical problems and notes regular menstrual cycles. The husband reports a history of chronic sinusitis and lower respiratory tract infections. Physical examination of the woman is unremarkable. Examination of the man reveals dextrocardia. Further work-up of the husband will most likely reveal?
- A. Azoospermia
- B. Germinal cell aplasia
- C. Immotile sperm (Correct Answer)
- D. Isolated gonadotropin deficiency
Explanation: **Explanation:** The clinical presentation of chronic sinusitis, recurrent lower respiratory tract infections, and **dextrocardia** (situs inversus) in a male with infertility is the classic triad of **Kartagener Syndrome**, a subset of **Primary Ciliary Dyskinesia (PCD)**. **1. Why "Immotile Sperm" is Correct:** PCD is an autosomal recessive disorder characterized by structural defects in the **dynein arms** of cilia and flagella. Since the tail of a spermatozoon is a modified flagellum sharing the same "9+2" microtubule structure as respiratory cilia, the defect leads to **impaired sperm motility (asthenozoospermia)**. While the sperm count is usually normal, they are unable to swim, leading to infertility. **2. Why Incorrect Options are Wrong:** * **Azoospermia:** This is the absence of sperm in the ejaculate. It is characteristic of **Cystic Fibrosis** (due to Congenital Bilateral Absence of the Vas Deferens - CBAVD), not PCD. * **Germinal cell aplasia (Sertoli cell-only syndrome):** This involves a lack of germ cells in the seminiferous tubules, leading to non-obstructive azoospermia. It is not associated with situs inversus or respiratory infections. * **Isolated gonadotropin deficiency:** Seen in **Kallmann Syndrome**, this presents with hypogonadotropic hypogonadism and anosmia, but not dextrocardia or bronchiectasis. **Clinical Pearls for NEET-PG:** * **Kartagener Triad:** Situs inversus, Bronchiectasis, and Sinusitis. * **Diagnostic Gold Standard:** Electron microscopy of ciliary ultrastructure (showing absent dynein arms) or genetic testing (DNAI1/DNAH5 mutations). * **Nasal Nitric Oxide:** Screening test for PCD; levels are typically very low. * **PCD vs. Cystic Fibrosis:** Both cause recurrent infections, but PCD presents with **situs inversus (50%)** and **immotile sperm**, whereas CF presents with **pancreatic insufficiency** and **CBAVD (azoospermia)**.
Question 224: Infants with cystic fibrosis (CF) are likely to develop which of the following complications?
- A. Meconium ileus (Correct Answer)
- B. Loose motions
- C. Vomiting
- D. Constipation
Explanation: **Explanation:** **Cystic Fibrosis (CF)** is an autosomal recessive disorder caused by mutations in the **CFTR gene**, leading to defective chloride transport and the production of abnormally thick, viscid secretions in various organs. **Why Meconium Ileus is Correct:** Meconium ileus is the earliest clinical manifestation of CF, occurring in approximately **15-20% of affected newborns**. Due to the lack of pancreatic enzymes and abnormal intestinal secretions, the meconium becomes extremely thick and "putty-like," causing a mechanical small bowel obstruction, typically at the level of the terminal ileum. On imaging, this often presents as a "ground-glass" appearance (Neuhauser’s sign). **Why Other Options are Incorrect:** * **B. Loose motions:** While CF patients suffer from malabsorption due to pancreatic insufficiency, they typically present with **steatorrhea** (foul-smelling, bulky, oily stools) rather than simple watery loose motions. * **C. Vomiting:** While vomiting can occur secondary to intestinal obstruction (like meconium ileus), it is a non-specific symptom and not a primary diagnostic complication of CF itself. * **D. Constipation:** While older children with CF may develop **Distal Intestinal Obstruction Syndrome (DIOS)**, which mimics constipation, meconium ileus is the classic, pathognomonic neonatal complication. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Sweat Chloride Test (Value >60 mEq/L). * **Most Common Mutation:** ΔF508. * **Pancreatic Status:** 85-90% of patients have exocrine pancreatic insufficiency. * **Infertility:** 95% of males are infertile due to Congenital Bilateral Absence of the Vas Deferens (CBAVD). * **Common Pathogens:** *Staphylococcus aureus* (early childhood) and *Pseudomonas aeruginosa* (most common cause of adult morbidity).
Question 225: According to WHO guidelines, which of the following is NOT an indication for hospital admission in pneumonia?
- A. Convulsions
- B. Persistent vomiting
- C. Chest indrawing (Correct Answer)
- D. Severe malnutrition
Explanation: ### Explanation The classification and management of childhood pneumonia under the **WHO Integrated Management of Childhood Illness (IMCI)** guidelines were updated to simplify treatment protocols. **1. Why "Chest Indrawing" is the correct answer:** According to the revised WHO guidelines, pneumonia is now classified into only two categories: * **Pneumonia:** Characterized by fast breathing and/or **chest indrawing**. These cases are managed with oral Amoxicillin at **home** (outpatient). * **Severe Pneumonia:** Characterized by pneumonia plus any **"General Danger Sign."** These cases require urgent referral and **hospital admission** for IV antibiotics. Since chest indrawing alone no longer mandates hospitalization, it is the correct answer to this "NOT an indication" question. **2. Analysis of Incorrect Options (Indications for Admission):** The following are **General Danger Signs** that signify "Severe Pneumonia" and necessitate immediate hospital admission: * **Convulsions (Option A):** Indicates neurological involvement or severe hypoxia. * **Persistent Vomiting (Option B):** The child cannot tolerate oral medication or hydration. * **Severe Malnutrition (Option D):** These children have compromised immunity and a high risk of mortality, requiring specialized inpatient care. * *Other signs include: Inability to breastfeed/drink, lethargy, or unconsciousness.* **3. NEET-PG High-Yield Pearls:** * **Fast Breathing Cut-offs:** * <2 months: ≥60 bpm * 2–12 months: ≥50 bpm * 12 months–5 years: ≥40 bpm * **Drug of Choice:** Oral **Amoxicillin** (40 mg/kg/dose twice daily for 5 days) is now the first-line treatment for non-severe pneumonia, replacing Cotrimoxazole. * **Stridor:** If a child has "Cough/Cold" plus **Stridor at rest**, it is also classified as Severe Disease requiring admission.
Question 226: Aerosolized ribavirin is used in the treatment of bronchiolitis with which causative organism?
- A. RSV (Respiratory Syncytial Virus) (Correct Answer)
- B. H. influenzae (Haemophilus influenzae)
- C. Streptococcus pneumoniae
- D. Streptococcus pyogenes
Explanation: **Explanation:** **1. Why RSV is Correct:** Respiratory Syncytial Virus (RSV) is the most common cause of acute bronchiolitis in infants. **Ribavirin** is a synthetic guanosine analog that inhibits viral RNA synthesis. While the routine use of ribavirin is no longer recommended for most cases of bronchiolitis due to high cost and limited efficacy, it is specifically indicated for **severe RSV infections** in high-risk patients (e.g., those with congenital heart disease, chronic lung disease, or immunocompromised states). It is administered via a Small Particle Aerosol Generator (SPAG-2). **2. Why Other Options are Incorrect:** * **B. H. influenzae:** This is a gram-negative bacterium. It is a common cause of epiglottitis and pneumonia, which require antibiotics (like Ceftriaxone), not antivirals. * **C. Streptococcus pneumoniae:** This is the most common cause of bacterial pneumonia in children. Treatment involves beta-lactam antibiotics (like Amoxicillin or Ampicillin). * **D. Streptococcus pyogenes:** Also known as Group A Strep, it typically causes pharyngitis, scarlet fever, or skin infections. It is highly sensitive to Penicillin. **3. High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Bronchiolitis is a clinical diagnosis characterized by a viral prodrome followed by increased respiratory effort and **wheezing** in children <2 years. * **CXR Finding:** Hyperinflation and flattening of the diaphragm. * **Treatment:** Primarily supportive (oxygenation and hydration). * **Prophylaxis:** **Palivizumab** (a monoclonal antibody against RSV F-protein) is used for prevention in high-risk preterm infants. * **Ribavirin Side Effect:** It is potentially teratogenic; pregnant healthcare workers should avoid exposure to the aerosolized drug.
Question 227: Which of the following is seen in cystic fibrosis?
- A. Low sweat chloride levels
- B. Elevated sweat chloride levels (Correct Answer)
- C. Low sweat sodium levels
- D. Elevated sweat potassium levels
Explanation: **Explanation:** Cystic Fibrosis (CF) is an autosomal recessive multisystem disorder caused by a mutation in the **CFTR (Cystic Fibrosis Transmembrane Conductance Regulator)** gene on chromosome 7. The CFTR protein functions as a chloride channel. **1. Why Option B is Correct:** In the sweat glands, the primary role of the CFTR protein is the **reabsorption** of chloride from the lumen back into the epithelial cells. When CFTR is defective, chloride cannot be reabsorbed and remains in the sweat. Since sodium follows chloride to maintain electrical neutrality, both chloride and sodium levels are elevated in the sweat. A sweat chloride level **>60 mmol/L** on two separate occasions (using the Pilocarpine Iontophoresis method) is the gold standard for diagnosis. **2. Why Other Options are Incorrect:** * **Options A & C:** Sweat chloride and sodium levels are characteristically **elevated**, not low. Low levels would be physiological or seen in conditions like adrenal insufficiency (though sodium is usually high there). * **Option D:** While sweat potassium may be mildly affected, it is not a diagnostic hallmark of CF. The primary defect specifically involves chloride transport. **NEET-PG High-Yield Pearls:** * **Most common mutation:** ΔF508 (Class II defect - protein misfolding). * **Earliest manifestation:** Meconium ileus (seen in 15-20% of newborns). * **Respiratory Hallmark:** Recurrent infections with *Staphylococcus aureus* (early childhood) and *Pseudomonas aeruginosa* (most common overall). * **Infertility:** 95% of males are infertile due to Congenital Bilateral Absence of Vas Deferens (CBAVD). * **Screening:** Immunoreactive Trypsinogen (IRT) levels in newborns.
Question 228: A child presents with recurrent sinusitis and repeated lung infections. Genetic testing shows a mutation in the CFTR gene. Which test is considered the gold standard to confirm the diagnosis?
- A. Chest X-ray
- B. Lung biopsy
- C. Nasal swab culture
- D. Sweat chloride test (Correct Answer)
Explanation: ***Sweat chloride test*** - It is recognized as the **gold standard** test for diagnosing Cystic Fibrosis in patients with suggestive symptoms or positive genetic screening (CFTR mutation). - The test measures non-reabsorbed chloride ions in the sweat, with levels **≥ 60 mEq/L** typically confirming the diagnosis due to **CFTR protein dysfunction**. *Lung biopsy* - This is an **invasive procedure** with significant risk and is not required for the standard diagnosis of Cystic Fibrosis. - While it might show findings consistent with severe CF (e.g., **bronchiectasis**), genetic testing and the sweat test provide definitive, less invasive confirmation. *Chest X-ray* - A Chest X-ray is a **radiographic imaging tool** used to monitor the progression of lung disease (e.g., presence of **hyperinflation** or **bronchiectasis**). - It is not a diagnostic test for the underlying CFTR defect and cannot definitively confirm the diagnosis of Cystic Fibrosis. *Nasal swab culture* - This test is used to identify common pathogens such as **Pseudomonas aeruginosa** or **Staphylococcus aureus**, which frequently colonize the airways of CF patients. - It is essential for managing **pulmonary exacerbations** and guiding antibiotic selection but does not assess CFTR function or establish the primary diagnosis.
Question 229: A 4-month-old infant is brought to the emergency department with a respiratory rate of 66 breaths per minute, along with chest indrawing and nasal flaring. There are no other significant findings. What is the most likely diagnosis?
- A. Severe pneumonia (Correct Answer)
- B. Pneumonia
- C. Severe asthma
- D. Common cold
Explanation: ***Severe pneumonia*** - According to **WHO/IMCI guidelines**, pneumonia in infants (2-12 months) is classified based on clinical signs. - This 4-month-old has a respiratory rate of **66 breaths/minute** (tachypnea, as RR ≥ 50 is abnormal) along with **chest indrawing** and **nasal flaring**. - The presence of **chest indrawing** is the defining feature that classifies this as **severe pneumonia** rather than simple fast-breathing pneumonia. - WHO classification: Fast breathing alone = pneumonia; Fast breathing + chest indrawing = **severe pneumonia**; danger signs (inability to feed, lethargy, cyanosis) = very severe disease. *Pneumonia* - Simple **pneumonia** (or fast-breathing pneumonia) would be diagnosed if the infant had only **tachypnea** (RR ≥ 50/min) **without** chest indrawing or other danger signs. - Since this infant has **chest indrawing**, it automatically upgrades the classification to severe pneumonia per WHO/IMCI criteria. - This distinction is clinically important as it determines management (severe pneumonia requires hospitalization and parenteral antibiotics). *Severe asthma* - **Asthma** is very uncommon in a 4-month-old infant, as it typically develops later following sensitization and recurrent episodes, often associated with atopy. - The hallmark feature of asthma is audible **wheezing**, which is not mentioned in this presentation. - While respiratory distress can occur in asthma, the absence of wheezing and the age make this diagnosis unlikely. *Common cold* - A **common cold** is a mild upper respiratory tract infection (URTI) that presents with nasal congestion, rhinorrhea, and possibly mild cough. - It does not cause significant respiratory distress such as severe **tachypnea** (RR 66/min) or **chest indrawing**. - The degree of respiratory compromise described here is far beyond what would be expected in a common cold.
Question 230: A 3-month-old child has a respiratory rate of 56/min with no chest indrawing and no danger signs. As per IMNCI what is the most appropriate diagnosis?
- A. Cold and cough
- B. Pneumonia (Correct Answer)
- C. Severe Pneumonia
- D. Allergy
Explanation: ***Pneumonia***- As per IMNCI guidelines, for a child aged 2 months up to 12 months, a respiratory rate of $\geq 50$ breaths/min is classified as **fast breathing**.- Since the child has **fast breathing** (56/min) but lacks **chest indrawing** or **danger signs**, the yellow category of **Pneumonia** is diagnosed.*Cold and cough*- This classification is utilized when the child has cough or cold but shows **no fast breathing** and **no chest indrawing** (Green classification, No Pneumonia).*Severe Pneumonia*- This classification requires the presence of **chest indrawing** or any **general danger sign** (e.g., lethargy, convulsions, inability to drink) alongside fast breathing or stridor (Red classification).*Allergy*- IMNCI focuses on classifying levels of severity of common infections (like respiratory infections, diarrhea, fever) for immediate management, and **allergy** is not one of the primary classification categories.
Practice by Chapter
Upper Respiratory Tract Infections
Practice Questions
Lower Respiratory Tract Infections
Practice Questions
Asthma Management
Practice Questions
Cystic Fibrosis
Practice Questions
Bronchiolitis
Practice Questions
Foreign Body Aspiration
Practice Questions
Sleep-Disordered Breathing
Practice Questions
Congenital Lung Malformations
Practice Questions
Pleural Diseases
Practice Questions
Tuberculosis in Children
Practice Questions
Chronic Lung Disease in Premature Infants
Practice Questions
Pulmonary Function Testing
Practice Questions
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