Respiratory Diseases Practice Questions

Q: What is the most common cause of ARDS in children?

Severe pneumonia with sepsis. **Explanation:** Acute Respiratory Distress Syndrome (ARDS) is a clinical syndrome characterized by acute onset of non-cardiogenic pulmonary edema and hypoxemia. In the pediatric population, the etiology is broadly categorized into direct (pulmonary) and indirect (extrapulmonary) lung injuries. **Why Option C is Correct:** According to the **Pediatric Acute Lung Injury Consensus Conference (PALICC)**, **severe pneumonia** is the most common cause of direct lung injury, while **sepsis** is the most common cause of indirect lung injury leading to ARDS in children. When combined, pneumonia-related sepsis accounts for the majority of pediatric ARDS cases globally. The underlying mechanism involves a massive inflammatory surge (cytokine storm) that increases alveolar-capillary permeability, leading to protein-rich fluid accumulation in the alveoli. **Why Other Options are Incorrect:** * **A. Aspiration:** While a significant cause of direct lung injury (especially gastric acid aspiration), it is statistically less frequent than infectious pneumonia. * **B. Injury (Trauma):** Physical trauma or pulmonary contusions can trigger ARDS, but these are more common in adolescents and adults rather than the general pediatric population. * **D. DIC:** Disseminated Intravascular Coagulation is typically a *complication* or a co-morbidity of sepsis rather than the primary inciting event for ARDS. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** Pediatric ARDS (PARDS) is defined by the **PALICC criteria**, which uses the **Oxygenation Index (OI)** or Oxygenation Saturation Index (OSI) instead of the PaO2/FiO2 ratio used in the adult Berlin criteria. * **Radiology:** Requires new infiltrates consistent with acute pulmonary parenchymal disease (not fully explained by heart failure or fluid overload). * **Management:** Lung-protective ventilation (low tidal volume: 3–6 mL/kg) and maintaining plateau pressures <28 cm H2O.

Q: A child with a three-day history of upper respiratory tract infection presents with stridor that decreases on lying down. What is the most probable diagnosis?

Laryngotracheobronchitis. ### Explanation **Laryngotracheobronchitis (Croup)** is the most common cause of acute upper airway obstruction in children (typically 6 months to 3 years). It is usually preceded by a prodrome of upper respiratory infection (URI) symptoms like rhinorrhea and low-grade fever. The characteristic **barking cough** and **inspiratory stridor** occur due to subglottic narrowing. A key clinical feature is that the stridor often **decreases when the child is lying down or resting** (as agitation increases respiratory effort and turbulence), though it classically worsens at night. **Why other options are incorrect:** * **Acute Epiglottitis:** This is a medical emergency characterized by a rapid onset, high fever, and the "4 Ds": Drooling, Dysphagia, Distress, and Dysphonia. Patients prefer the "tripod position" and stridor **worsens** when lying supine due to the epiglottis falling back over the glottis. * **Foreign Body Aspiration:** This typically presents with a sudden, choking episode in a previously healthy child without a viral prodrome (no 3-day history of URI). * **Retropharyngeal Abscess:** While it presents with stridor and fever, it is distinguished by severe sore throat, neck stiffness (torticollis), and muffled "hot potato" voice. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Most common virus is **Parainfluenza type 1**. * **Radiology:** The classic X-ray finding is the **"Steeple Sign"** (subglottic narrowing) on the Anteroposterior (AP) view of the neck. * **Management:** Mild cases are managed with oral Dexamethasone. Severe cases (stridor at rest) require **Nebulized Adrenaline** and steroids. * **Westley Croup Score** is used to assess severity.

Q: Acute onset of cough, stridor, and respiratory distress in the absence of fever is suggestive of what condition?

Foreign body aspiration. ### Explanation **Correct Answer: A. Foreign Body Aspiration (FBA)** The hallmark of Foreign Body Aspiration is the **sudden, acute onset** of respiratory symptoms (cough, choking, stridor, or wheezing) in a previously healthy child. The **absence of fever** is a critical clinical differentiator, as it points toward a mechanical obstruction rather than an infectious process like croup or epiglottitis. In children aged 1–3 years, the "penetration syndrome" (sudden choking episode) is highly suggestive of FBA. **Why the other options are incorrect:** * **B. Acute Asthma:** While asthma causes respiratory distress and cough, it typically presents with recurrent episodes of expiratory wheezing rather than inspiratory stridor. It is often preceded by viral triggers or allergen exposure. * **C. Aspiration Pneumonia:** This is an inflammatory/infectious process resulting from the inhalation of gastric contents or oropharyngeal flora. It usually presents with **fever**, productive cough, and constitutional symptoms, rather than an instantaneous onset of stridor. * **D. Primary Complex:** This refers to the initial focus of pulmonary Tuberculosis. It is a chronic condition characterized by low-grade fever, weight loss, and a persistent cough, rather than acute respiratory distress. **NEET-PG High-Yield Pearls:** * **Most common site:** Right main bronchus (due to it being wider, shorter, and more vertical than the left). * **Most common age group:** 1 to 3 years (toddlers). * **Radiological sign:** "Check-valve" obstruction leading to **obstructive emphysema** (hyperlucency) on the affected side. * **Gold Standard Management:** Rigid Bronchoscopy (both diagnostic and therapeutic). Flexible bronchoscopy is preferred only for distal foreign bodies.

Q: A 2-month-old child has a respiratory rate of 45/minute. The child has not been accepting feeds for the last 4 days and shows signs of dehydration. Which type of pneumonia is this?

Severe pneumonia. ### Explanation The classification of pneumonia in children is based on the **WHO Integrated Management of Neonatal and Childhood Illness (IMNCI)** guidelines. **Why "Severe Pneumonia" is correct:** According to IMNCI guidelines for a child aged 2 months to 5 years, the presence of any **"General Danger Sign"** automatically classifies the condition as **Severe Pneumonia**. These signs include: 1. Inability to drink or breastfeed (as seen in this patient). 2. Persistent vomiting. 3. Convulsions. 4. Lethargy or unconsciousness. 5. Presence of chest indrawing. Even though the child’s respiratory rate (45/min) is technically normal for a 2-month-old (threshold for tachypnea is $\geq$ 50/min), the **inability to feed** is a critical danger sign that mandates hospitalization and parenteral antibiotics, categorizing it as Severe Pneumonia. **Analysis of Incorrect Options:** * **No Pneumonia:** Classified if there is no fast breathing AND no general danger signs. * **Pneumonia:** Classified if there is fast breathing ($\geq$ 50/min for 2–12 months) but **no** general danger signs and **no** chest indrawing. * **Very Severe Pneumonia:** This term was used in older WHO classifications. Under current IMNCI guidelines, "Severe Pneumonia" and "Very Severe Disease" are often grouped to simplify treatment protocols (referring to those requiring IV antibiotics). **NEET-PG High-Yield Pearls:** * **Tachypnea Cut-offs (IMNCI):** * < 2 months: $\geq$ 60/min * 2–12 months: $\geq$ 50/min * 12 months–5 years: $\geq$ 40/min * **Treatment:** Severe pneumonia requires **Injectable Ampicillin and Gentamicin** (or Ceftriaxone) as first-line therapy. * **Key Indicator:** In a child < 2 months, even "Chest Indrawing" is classified as Severe Disease/Pneumonia.

Q: A 5-year-old child suddenly develops stridor. Which one of the following would be the most likely diagnosis?

Foreign body aspiration. ### 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.

Q: 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?

Immotile sperm. **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)**.

Q: Which of the following is NOT an indication for admission in pneumonia?

Fever of 39°C. In the management of childhood pneumonia, the decision to admit is based on the **IMNCI (Integrated Management of Neonatal and Childhood Illness)** and WHO guidelines, which prioritize clinical signs of respiratory distress and systemic danger signs over isolated physiological parameters like temperature. ### Why Option A is Correct **Fever (even 39°C/102.2°F)** is a common symptom of pneumonia but is **not** an independent indication for hospitalization. In the absence of other "danger signs," a child with a cough and fast breathing (Pneumonia) can be managed at home with oral antibiotics (e.g., Amoxicillin) and supportive care for fever (e.g., Paracetamol). ### Why the Other Options are Incorrect Options B, C, and D are all classified as **"Severe Pneumonia"** or "Very Severe Disease," necessitating urgent referral and inpatient parenteral antibiotics: * **Cyanosis (Option B):** Indicates hypoxemia and impending respiratory failure. * **Chest Retraction (Option C):** Specifically, lower chest wall indrawing is a hallmark sign of severe respiratory distress in children. * **Not Feeding Well (Option D):** Inability to drink or breastfeed is a "General Danger Sign" indicating systemic compromise or exhaustion. ### High-Yield Clinical Pearls for NEET-PG * **Fast Breathing Thresholds:** <2 months: ≥60/min; 2–12 months: ≥50/min; 12–60 months: ≥40/min. * **IMNCI Classification:** * **Pneumonia:** Fast breathing only → Home care (Oral Amoxicillin). * **Severe Pneumonia:** Any danger sign (indrawing, cyanosis, lethargy, inability to feed, convulsions) → Hospitalize (IV Ampicillin + Gentamicin). * **Stridor** in a calm child is also an indication for immediate admission.

Q: Aerosolized ribavirin is used in the treatment of bronchiolitis with which causative organism?

RSV (Respiratory Syncytial Virus). **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.

Q: Which of the following is seen in cystic fibrosis?

Elevated sweat chloride levels. **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.

Q: 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?

Sweat chloride test. ***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 1

What is the most common cause of ARDS in children?

Accepted Answer

Severe pneumonia with sepsis

Answer

Aspiration

Answer

Injury

Answer

DIC

Question 2

A child with a three-day history of upper respiratory tract infection presents with stridor that decreases on lying down. What is the most probable diagnosis?

Accepted Answer

Laryngotracheobronchitis

Answer

Acute Epiglottitis

Answer

Foreign body aspiration

Answer

Retropharyngeal abscess

Question 3

Acute onset of cough, stridor, and respiratory distress in the absence of fever is suggestive of what condition?

Accepted Answer

Foreign body aspiration

Answer

Acute asthma

Answer

Aspiration pneumonia

Answer

Primary complex

Question 4

A 2-month-old child has a respiratory rate of 45/minute. The child has not been accepting feeds for the last 4 days and shows signs of dehydration. Which type of pneumonia is this?

Accepted Answer

Severe pneumonia

Answer

No pneumonia

Answer

Pneumonia

Answer

Very severe pneumonia

Question 5

A 5-year-old child suddenly develops stridor. Which one of the following would be the most likely diagnosis?

Accepted Answer

Foreign body aspiration

Answer

Laryngomalacia

Answer

Acute laryngotracheobronchitis

Answer

Acute epiglottitis

Question 6

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?

Accepted Answer

Immotile sperm

Answer

Azoospermia

Answer

Germinal cell aplasia

Answer

Isolated gonadotropin deficiency

Question 7

Which of the following is NOT an indication for admission in pneumonia?

Accepted Answer

Fever of 39°C

Answer

Cyanosis

Answer

Chest retraction

Answer

Not feeding well

Question 8

Aerosolized ribavirin is used in the treatment of bronchiolitis with which causative organism?

Accepted Answer

RSV (Respiratory Syncytial Virus)

Answer

H. influenzae (Haemophilus influenzae)

Answer

Streptococcus pneumoniae

Answer

Streptococcus pyogenes

Question 9

Which of the following is seen in cystic fibrosis?

Accepted Answer

Elevated sweat chloride levels

Answer

Low sweat chloride levels

Answer

Low sweat sodium levels

Answer

Elevated sweat potassium levels

Question 10

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?

Accepted Answer

Sweat chloride test

Answer

Chest X-ray

Answer

Lung biopsy

Answer

Nasal swab culture

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

On this page

Practice by Chapter

Want unlimited practice?