Respiratory Diseases Practice Questions

Q: A 4-year-old child presents with sudden onset of sore throat, hoarseness, and difficulty in breathing. The patient has a high temperature, is drooling, and prefers to lean forward. What is the most likely diagnosis?

Acute epiglottitis. **Explanation:** The clinical presentation described is a classic "textbook" case of **Acute Epiglottitis**, a life-threatening medical emergency. The diagnosis is based on the **"4 Ds"**: Drooling, Dysphagia, Distress, and Dysphonia (muffled "hot potato" voice). The child’s preference to lean forward (the **Tripod position**) is a compensatory mechanism to maintain airway patency. The sudden onset and high-grade fever help differentiate it from viral causes like Croup. **Why the other options are incorrect:** * **Bronchiolitis:** Typically affects infants (<2 years) and presents with lower respiratory symptoms like wheezing and fine crackles, following a viral prodrome. * **Streptococcal pharyngitis:** While it causes sore throat and fever, it does not typically cause acute respiratory distress, drooling, or airway obstruction. * **Whooping cough (Pertussis):** Characterized by paroxysmal bouts of coughing followed by an inspiratory "whoop." It does not present with acute upper airway obstruction or drooling. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Historically *Haemophilus influenzae* type b (Hib) was the most common cause; however, incidence has dropped significantly due to vaccination. * **Radiology:** Lateral neck X-ray shows the **"Thumb sign"** (swollen epiglottis). * **Management:** The priority is **airway stabilization** (intubation or tracheostomy) in a controlled environment (OR). Never examine the throat with a tongue depressor, as it may trigger fatal laryngospasm. * **Definitive Diagnosis:** Direct laryngoscopy (showing a "cherry-red" epiglottis).

Q: A 5-year-old child weighing 20 kgs presents with a respiratory rate of 54 breaths per minute. Based on these findings, how would this condition be classified regarding pneumonia?

Pneumonia. ### Explanation The classification of respiratory infections in children is a high-yield topic based on the **WHO Integrated Management of Childhood Illness (IMCI)** guidelines. **1. Why "Pneumonia" is the correct answer:** The classification is primarily based on the child's age and the presence of **fast breathing** or **chest indrawing**. For a child aged 12 months to 5 years, fast breathing is defined as a respiratory rate (RR) of **≥ 40 breaths per minute**. * **Patient Data:** Age 5 years, RR 54 bpm. * Since 54 is greater than 40, and there is no mention of "danger signs" or "chest indrawing," the child is classified as having **Pneumonia**. **2. Why other options are incorrect:** * **No pneumonia:** This classification is for children with a cough or cold but a normal respiratory rate (< 40 bpm for this age group). * **Severe pneumonia:** This requires the presence of **chest indrawing** (subcostal retraction) or any **general danger signs** (inability to drink/breastfeed, persistent vomiting, lethargy/unconsciousness, or convulsions). Fast breathing alone does not qualify as severe. * **Very severe pneumonia:** This term was used in older guidelines; current IMCI guidelines categorize cases with danger signs simply as "Severe Pneumonia/Very Severe Disease." **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 * **Treatment:** According to IMCI, "Pneumonia" is treated with **Oral Amoxicillin** (40 mg/kg/dose twice daily) for 5 days at home. "Severe Pneumonia" requires hospitalization and **IV Ampicillin and Gentamicin**. * **Note:** Weight (20 kg) is provided to distract you; the classification depends on age and clinical signs, not weight.

Q: What is the most common lobe involved in congenital lobar emphysema?

Left upper lobe. **Explanation:** **Congenital Lobar Emphysema (CLE)**, also known as Congenital Lobar Overinflation, is a developmental anomaly characterized by the progressive overdistension of one or more pulmonary lobes. This occurs due to a "ball-valve" mechanism, where air enters during inspiration but cannot escape during expiration, leading to air trapping and compression of the surrounding lung tissue. **1. Why Left Upper Lobe (LUL) is Correct:** The **Left Upper Lobe** is the most frequently affected site, accounting for approximately **40–50%** of all cases. The exact reason for this predilection is not fully understood, but it is often associated with localized bronchomalacia (deficiency of bronchial cartilage) or extrinsic vascular compression (e.g., by a patent ductus arteriosus or anomalous pulmonary artery). **2. Analysis of Incorrect Options:** * **Right Middle Lobe (RML):** This is the second most common site, involved in about **30–35%** of cases. * **Right Upper Lobe (RUL):** This is the third most common site, involved in approximately **20%** of cases. * **Lower Lobes:** Involvement of the lower lobes (Left or Right) is extremely rare (less than 1–5%). **3. NEET-PG High-Yield Clinical Pearls:** * **Presentation:** Most infants present within the first 6 months of life with respiratory distress, wheezing, and asymmetrical chest expansion. * **Radiology:** The classic X-ray finding is a **hyperlucent, overdistended lobe** with a mediastinal shift to the contralateral side and depression of the ipsilateral diaphragm. * **Management:** Surgical lobectomy is the definitive treatment for symptomatic patients. * **Key Association:** Up to 10% of patients with CLE have associated **congenital heart disease** (most commonly VSD or PDA).

Q: After repeated infections manifested by cough, fever, and consolidation in lungs, the diagnosis of intralobar sequestration was established for a child. Sequestration of lung is seen MOST commonly in?

Posterior basal segment of left lung. **Explanation:** **Pulmonary Sequestration** is a rare congenital anomaly characterized by a non-functioning mass of lung tissue that lacks normal communication with the tracheobronchial tree and receives its arterial blood supply from the systemic circulation (usually the thoracic or abdominal aorta). **Why the correct answer is right:** The **posterior basal segment of the left lower lobe** is the most common site for pulmonary sequestration, accounting for approximately **60–90%** of cases. This predilection for the left side and the lower lobes is a classic anatomical hallmark. Specifically, **Intralobar Sequestration (ILS)**—which presents later in childhood with recurrent infections as seen in this clinical vignette—is found in the left lower lobe in about 75% of instances. **Why the incorrect options are wrong:** * **A & B (Right upper/lower lobe):** While sequestration can occur on the right side, it is significantly less frequent than on the left. Upper lobe involvement is extremely rare (less than 2%). * **C (Lateral basal segment):** Although sequestration occurs in the lower lobes, the **posterior** basal segment is statistically more common than the lateral basal segment. **High-Yield Clinical Pearls for NEET-PG:** * **Types:** * **Intralobar (ILS):** Located within the normal visceral pleura; presents with recurrent pneumonia/abscess; venous drainage is usually to the **pulmonary veins**. * **Extralobar (ELS):** Has its own pleural investment; often associated with other anomalies (e.g., Diaphragmatic hernia); venous drainage is to the **systemic veins** (Azygos/Hemiazygos). * **Gold Standard Diagnosis:** CT Angiography (to visualize the aberrant systemic arterial supply). * **Management:** Surgical resection (lobectomy for ILS or sequestrectomy for ELS) is the treatment of choice to prevent recurrent infections and massive hemoptysis.

Q: A child presents with respiratory distress and failure to thrive. His sweat chloride levels were estimated at 35 meq/L and 41 meq/L. What is the next best test to confirm the diagnosis of cystic fibrosis?

CT chest. **Explanation:** The diagnosis of Cystic Fibrosis (CF) is primarily clinical, supported by evidence of CFTR dysfunction. In this case, the child has suggestive symptoms (respiratory distress, failure to thrive) but **borderline sweat chloride levels** (30–59 mmol/L). **Why CT Chest is the correct answer:** According to the latest diagnostic algorithms (including the Cystic Fibrosis Foundation consensus), if sweat chloride results are intermediate/borderline, the next step is to look for objective evidence of CFTR dysfunction or characteristic organ involvement. High-resolution CT (HRCT) of the chest is highly sensitive for detecting early structural changes like **bronchiectasis**, which provides the clinical evidence needed to support the diagnosis in the "gray zone" of sweat testing. **Analysis of Incorrect Options:** * **Nasal Transmembrane Potential Difference (NPD):** While this measures CFTR function, it is technically demanding, rarely available in most centers, and usually reserved for cases where genetic testing is also inconclusive. * **DNA analysis for F508del mutation:** While F508del is the most common mutation, a negative result for this specific mutation does not rule out CF, as there are over 2,000 other possible mutations. Complete gene sequencing would be required instead. * **72-hour fecal fat estimation:** This confirms malabsorption/pancreatic insufficiency but is non-specific and does not confirm CF as the primary etiology. **Clinical Pearls for NEET-PG:** * **Sweat Chloride Cut-offs:** <30 mmol/L (Unlikely), 30–59 mmol/L (Intermediate/Possible), ≥60 mmol/L (Diagnostic). * **Gold Standard:** Sweat Chloride by Pilocarpine Iontophoresis. * **Most Common Mutation:** ΔF508 (Class II mutation - protein misfolding). * **Newborn Screening:** Immunoreactive Trypsinogen (IRT) is the initial screening test.

Q: A 9-month-old child presents with cough and coryza for 2 days. For the past day, the child has had noisy breathing that worsens with crying. On examination, stridor is noted. What is the most likely diagnosis?

Croup. **Explanation:** The clinical presentation of a 9-month-old with a prodrome of cough and coryza followed by the sudden onset of stridor and noisy breathing (which worsens with agitation or crying) is classic for **Croup (Laryngotracheobronchitis)**. **Why Croup is the correct answer:** Croup is a viral infection (most commonly **Parainfluenza virus type 1**) that causes subglottic edema. The narrowing of the upper airway leads to the characteristic **inspiratory stridor**, barking cough, and hoarseness. Symptoms typically worsen at night and when the child is distressed (crying), as increased airflow through a narrowed subglottis creates more turbulence. **Why other options are incorrect:** * **Bronchiolitis:** Primarily affects the lower airways (bronchioles). It presents with wheezing and fine crepitations rather than stridor. * **Asthma:** Characterized by recurrent episodes of expiratory wheezing and cough. It is rare to diagnose asthma in a 9-month-old with a first-time stridor episode. * **Laryngomalacia:** This is a congenital cause of stridor. While it also worsens with crying/feeding, it typically presents within the first few weeks of life and is chronic, not preceded by a viral prodrome (fever/coryza). **High-Yield Clinical Pearls for NEET-PG:** * **X-ray Finding:** The "Steeple Sign" (subglottic narrowing) on an AP view of the neck. * **Westley Score:** Used to clinically grade the severity of Croup. * **Management:** Mild cases are managed with a single dose of **Dexamethasone** (0.6 mg/kg). Severe cases with stridor at rest require **Nebulized Adrenaline** (Racepinephrine) for rapid vasoconstriction and edema reduction.

Q: A seven-year-old child presents with recurrent chest infections and exocrine pancreatic insufficiency. Sweat chloride levels have been observed between 40-60 mmol/L on two separate occasions. Which of the following tests should be performed next to support the diagnosis of cystic fibrosis?

Demonstrate an abnormal nasal potential difference. **Explanation:** The clinical presentation of recurrent respiratory infections and exocrine pancreatic insufficiency is highly suggestive of **Cystic Fibrosis (CF)**. However, the sweat chloride levels (40-60 mmol/L) fall into the **intermediate/borderline range** (Normal: <40 mmol/L; Diagnostic: ≥60 mmol/L). **Why Option B is Correct:** According to the diagnostic criteria for CF, if a patient has clinical features but borderline sweat chloride results, the diagnosis must be confirmed by demonstrating **CFTR dysfunction** through ancillary tests. **Nasal Potential Difference (NPD)** measures the voltage across the nasal epithelium; patients with CF show a characteristic pattern (more negative baseline and failure to respond to chloride-free/isoproterenol solutions). This is a gold-standard physiological test for CFTR function when sweat tests are inconclusive. **Why Other Options are Incorrect:** * **Option A:** Repeating the sweat chloride test is unlikely to be helpful as it has already been performed twice with borderline results. * **Option C:** While DNA analysis is diagnostic, there are over 2,000 mutations. Testing only for the **F508del** (the most common mutation) may miss other mutations. A negative F508 test does not rule out CF. * **Option D:** Fecal fat excretion confirms malabsorption/pancreatic insufficiency but is not specific to CF and does not confirm the underlying genetic diagnosis. **Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Sweat Chloride ≥60 mmol/L on two occasions. * **Intermediate Range:** 30–59 mmol/L (infants <6 months) or 40–59 mmol/L (older children). * **Most Common Mutation:** ΔF508 (Class II mutation - protein misfolding). * **NPD vs. ICM:** If NPD is unavailable, **Intestinal Current Measurement (ICM)** on a rectal biopsy is another functional test for CFTR activity.

Question 1

A 4-year-old child presents with sudden onset of sore throat, hoarseness, and difficulty in breathing. The patient has a high temperature, is drooling, and prefers to lean forward. What is the most likely diagnosis?

Accepted Answer

Acute epiglottitis

Answer

Bronchiolitis

Answer

Streptococcal pharyngitis

Answer

Whooping cough

Question 2

A 5-year-old child weighing 20 kgs presents with a respiratory rate of 54 breaths per minute. Based on these findings, how would this condition be classified regarding pneumonia?

Accepted Answer

Pneumonia

Answer

No pneumonia

Answer

Severe pneumonia

Answer

Very severe pneumonia

Question 3

What is the most common lobe involved in congenital lobar emphysema?

Accepted Answer

Left upper lobe

Answer

Right upper lobe

Answer

Right middle lobe

Answer

Left lower lobe

Question 4

Which of the following is not a cause of lung abscess in children?

Accepted Answer

E. Histolytica

Answer

Pneumococcus

Answer

Staphylococcus

Answer

Klebsiella

Question 5

After repeated infections manifested by cough, fever, and consolidation in lungs, the diagnosis of intralobar sequestration was established for a child. Sequestration of lung is seen MOST commonly in?

Accepted Answer

Posterior basal segment of left lung

Answer

Right upper lobe

Answer

Right lower lobe

Answer

Lateral basal segment

Question 6

A 9-month-old child presented with characteristic "barking" cough and hoarseness of voice. She had a history of rhinorrhoea, pharyngitis, mild cough, and low-grade fever for 1-3 days, with symptoms worsening at night. On examination, she had a normal to moderately inflamed pharynx, increased respiratory rate, nasal flaring, suprasternal, infrasternal, and intercostal retractions, and continuous inspiratory stridor. X-ray of the neck was also performed. All of the following statements are true about the treatment of this condition except:

Accepted Answer

Oral steroids are not beneficial in mild croup.

Answer

Nebulized racemic epinephrine is an accepted treatment for moderate or severe croup.

Answer

Patients can be safely discharged home after a 2-3 hour period of observation provided they have no stridor at rest, have normal air entry, normal pulse oximetry, normal level of consciousness, and have received steroids.

Answer

Corticosteroids decrease the edema in the laryngeal mucosa through their anti-inflammatory action.

Question 7

A child presents with respiratory distress and failure to thrive. His sweat chloride levels were estimated at 35 meq/L and 41 meq/L. What is the next best test to confirm the diagnosis of cystic fibrosis?

Accepted Answer

CT chest

Answer

Nasal transmembrane potential difference

Answer

DNA analysis for F508del mutation

Answer

72-hour fecal fat estimation

Question 8

A 9-month-old child presents with cough and coryza for 2 days. For the past day, the child has had noisy breathing that worsens with crying. On examination, stridor is noted. What is the most likely diagnosis?

Accepted Answer

Croup

Answer

Bronchiolitis

Answer

Asthma

Answer

Laryngomalacia

Question 9

A 4-month-old boy presents with fever and cough for 3 days. On examination, he has rhonchi, a respiratory rate of 48/min, and no chest indrawing. Which of the following statements is false?

Accepted Answer

The child has pneumonia

Answer

Treatment for wheeze

Answer

Antibiotics should not be given

Answer

Fever should be treated

Question 10

A seven-year-old child presents with recurrent chest infections and exocrine pancreatic insufficiency. Sweat chloride levels have been observed between 40-60 mmol/L on two separate occasions. Which of the following tests should be performed next to support the diagnosis of cystic fibrosis?

Accepted Answer

Demonstrate an abnormal nasal potential difference

Answer

Repeat sweat chloride levels on a different day

Answer

Demonstrate the F508 mutation by DNA analysis

Answer

Demonstrate abnormal 72-hour fecal fat excretion

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

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