Respiratory Diseases Practice Questions

Q: A 2-year-old boy presents with a history of sudden onset respiratory difficulty and stridor. On auscultation, there are decreased breath sounds and wheezing on the right side. An X-ray shows a right opaque hemithorax. What is the most likely diagnosis?

Foreign body aspiration. ### Explanation **Correct Answer: D. Foreign body aspiration** **Why it is correct:** The clinical triad of **sudden onset** respiratory distress, **stridor**, and **unilateral** findings (decreased breath sounds/wheezing) in a toddler is classic for foreign body aspiration (FBA). In children, the right main bronchus is more vertical, making it the most common site for aspirated objects. The "opaque hemithorax" on X-ray indicates **obstructive atelectasis** (collapse). When a foreign body completely occludes a bronchus, the air distal to the obstruction is absorbed, leading to lung collapse and a radio-opaque appearance. **Why incorrect options are wrong:** * **Pneumothorax:** This would present with sudden distress, but the X-ray would show **hyperlucency** (increased darkness) and absent lung markings, not an opaque hemithorax. * **Acute Epiglottitis:** While it causes sudden stridor, it is characterized by high fever, drooling, and a "tripod position." It is a supraglottic airway obstruction and would not cause unilateral lung findings or an opaque hemithorax. * **Massive Pleural Effusion:** While this causes an opaque hemithorax, the onset is typically **gradual** (associated with pneumonia or malignancy), not sudden. It also usually causes a mediastinal shift *away* from the opacification, whereas collapse (FBA) shifts it *towards* the lesion. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Right main bronchus. * **Most common age:** 1–3 years (toddlers). * **X-ray findings:** Can vary from normal (most common) to obstructive emphysema (check-valve effect) or collapse (stop-valve effect). * **Gold Standard Diagnosis & Management:** Rigid Bronchoscopy (Emergency). * **Key sign:** "Holzknecht sign" (mediastinal swing towards the affected side during inspiration on fluoroscopy).

Q: Pneumatoceles on chest radiographs in a child with pneumonia are most commonly associated with which organism?

Staphylococcus. **Explanation:** The presence of **pneumatoceles** (thin-walled, air-filled cysts within the lung parenchyma) is a classic radiologic hallmark of **Staphylococcal pneumonia**. **1. Why Staphylococcus is Correct:** *Staphylococcus aureus* produces specific toxins and enzymes (such as Panton-Valentine Leukocidin) that cause significant tissue necrosis and inflammation. This leads to a "check-valve" mechanism where air enters the interstitial space during inspiration but becomes trapped during expiration. This localized alveolar rupture and air trapping result in the formation of pneumatoceles. While they often appear alarming on X-ray, they are usually transient and resolve spontaneously with appropriate antibiotic therapy. **2. Why Other Options are Incorrect:** * **B. Pneumococcus (*S. pneumoniae*):** The most common cause of community-acquired pneumonia in children. It typically presents as lobar consolidation and is more frequently associated with pleural effusions rather than pneumatoceles. * **C. Streptococcus (*S. pyogenes*):** Often causes rapidly progressive pneumonia with early, large pleural effusions and empyema, but pneumatoceles are rare. * **D. Hemophilus influenzae:** Usually presents as bronchopneumonia or lobar pneumonia. Since the introduction of the HiB vaccine, its incidence has significantly decreased, and it is not typically associated with cavitary or cystic lesions. **3. NEET-PG High-Yield Pearls:** * **Triad of Staphylococcal Pneumonia:** Pneumatocele, Pleural effusion, and Empyema (often associated with pyopneumothorax). * **Management:** Most pneumatoceles are asymptomatic and require **conservative management** (observation); they should not be drained unless they cause tension symptoms or become infected. * **Other causes of pneumatoceles:** Hydrocarbon aspiration, trauma, and *Pneumocystis jirovecii* (in immunocompromised hosts).

Q: A 9-month-old infant presents with a 2-day history of fever, cough, and breathlessness following an upper respiratory infection. The infant is febrile and has a respiratory rate of 80/min, with intercostal and subcostal retractions and extensive rhonchi on auscultation. A chest X-ray reveals a hyperinflated chest. What is the most likely diagnosis?

Bronchiolitis. **Explanation:** The clinical presentation is classic for **Acute Bronchiolitis**, the most common lower respiratory tract infection in infants (peak age 2–6 months). It is typically caused by **Respiratory Syncytial Virus (RSV)**. **Why Bronchiolitis is correct:** 1. **Age:** It primarily affects children under 2 years. 2. **Prodrome:** It starts with a viral URI (fever, cough) followed by lower respiratory distress. 3. **Pathophysiology:** Inflammation and edema of small airways lead to obstruction. This causes **air trapping**, which manifests as **hyperinflation** on X-ray and widespread **rhonchi/wheezing** on auscultation. A respiratory rate of 80/min indicates significant distress. **Why other options are incorrect:** * **Bronchial asthma:** Rarely diagnosed in a 9-month-old during the first episode. Asthma is a recurrent condition; bronchiolitis is the "first episode of wheezing" in an infant. * **Foreign body aspiration:** Usually presents with sudden onset choking and asymmetrical breath sounds/localized wheeze, not a febrile viral prodrome. * **Bacterial pneumonia:** Typically presents with high fever, toxic appearance, and localized crepitations or dullness on percussion, rather than diffuse wheezing and hyperinflation. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** RSV (followed by Rhinovirus). * **X-ray findings:** Hyperlucency, depressed diaphragm, and horizontal ribs. * **Treatment:** Primarily supportive (oxygenation and hydration). Routine use of bronchodilators, steroids, or antibiotics is **not** recommended. * **Risk Factor:** Prematurity and congenital heart disease increase severity.

Q: A 6-month-old child presents with a cough and a respiratory rate of 50 breaths per minute. What does this finding indicate?

Pneumonia. This question tests your knowledge of the **WHO Integrated Management of Neonatal and Childhood Illness (IMNCI)** guidelines for classifying respiratory infections in children aged 2 months to 5 years. ### **Explanation of the Correct Answer** According to IMNCI criteria, the primary indicator for **Pneumonia** is **Fast Breathing** (Tachypnea) in the absence of chest indrawing or danger signs. The thresholds for fast breathing are age-specific: * **< 2 months:** ≥ 60 breaths/min * **2 to 12 months:** ≥ 50 breaths/min * **12 months to 5 years:** ≥ 40 breaths/min In this case, the 6-month-old child has a respiratory rate of 50 bpm, which meets the exact cutoff for fast breathing, thus classifying the condition as **Pneumonia**. ### **Analysis of Incorrect Options** * **A. No pneumonia:** This classification is used when a child has a cough/cold but the respiratory rate is *below* the age-specific threshold (e.g., < 50 bpm for a 6-month-old) and no chest indrawing is present. * **C. Severe pneumonia:** This requires the presence of **Chest Indrawing** (subcostal retraction) in addition to cough or fast breathing. * **D. Very severe pneumonia:** This classification (often grouped with Severe Pneumonia in newer guidelines) is used if any **General Danger Signs** are present, such as inability to drink/breastfeed, lethargy, unconsciousness, or convulsions. ### **NEET-PG High-Yield Pearls** * **Counting Rule:** Always count the respiratory rate for a full **60 seconds** when the child is calm. * **Treatment:** IMNCI recommends oral **Amoxicillin** (40 mg/kg/dose twice daily for 5 days) for "Pneumonia" managed at home. * **Stridor:** If a child has stridor while calm but no danger signs, it is also classified as Severe Pneumonia and requires urgent referral.

Q: A child presents with respiratory distress and a chest X-ray shows multiple air-filled spaces. What is the most likely diagnosis to be excluded from the differential diagnosis?

Congenital lobar aplasia of the lung. **Explanation:** The core of this question lies in distinguishing between pathologies that create **cystic/air-filled spaces** on a chest X-ray versus those that result in a **lack of lung tissue**. **1. Why "Congenital Lobar Aplasia" is the correct answer:** In **Congenital Lobar Aplasia**, there is a complete absence of the lung parenchyma and its associated bronchus and vessels. On a chest X-ray, this typically presents as an **opaque hemithorax** (due to the absence of air-filled tissue) with a mediastinal shift toward the affected side. It does *not* produce multiple air-filled spaces; therefore, it is the outlier that should be excluded from this differential. **2. Analysis of Incorrect Options (Differential for Cystic Lucencies):** * **Congenital Lung Cyst:** These are fluid or air-filled structures that appear as thin-walled, radiolucent circles on X-ray. * **Congenital Diaphragmatic Hernia (CDH):** Abdominal contents (bowel loops) herniate into the thoracic cavity. On X-ray, these air-filled bowel loops mimic multiple cystic spaces. This is a classic "masquerader" of lung cysts. * **Congenital Pulmonary Adenomatoid Malformation (CPAM/CCAM):** This is a multicystic mass of non-functioning lung tissue. Type I and II CPAM characteristically show multiple air-filled cysts of varying sizes on imaging. **NEET-PG High-Yield Pearls:** * **CDH:** Most common site is **Bochdalek** (posterolateral, usually left side). Scaphoid abdomen + respiratory distress is the classic triad. * **Congenital Lobar Emphysema (CLE):** Often confused with cysts, but it shows **hyperlucency** of a single lobe (usually Left Upper Lobe) with mass effect, rather than multiple distinct cysts. * **Pneumatocele:** Often seen post-Staphylococcal pneumonia; these are acquired thin-walled air cysts that can mimic congenital malformations.

Q: An 11-month-old child presents with complaints of respiratory distress. On examination, there are bilateral crepitations and wheezing. Which of the following is the most likely cause?

RSV. **Explanation:** The clinical presentation of an 11-month-old child with respiratory distress, **bilateral crepitations, and wheezing** is classic for **Acute Bronchiolitis**. **1. Why RSV is the Correct Answer:** Respiratory Syncytial Virus (RSV) is the most common cause of bronchiolitis worldwide, accounting for approximately 70-80% of cases. It typically affects children under 2 years of age (peak incidence at 3–6 months). The pathophysiology involves inflammation of the small airways (bronchioles), leading to edema, mucus production, and necrosis of epithelial cells. This results in the characteristic clinical finding of **polyphonic wheezing** and fine crackles. **2. Why Other Options are Incorrect:** * **Pneumonia:** While it causes respiratory distress and crepitations, it typically presents with high fever and localized (unilateral) findings. Wheezing is not a hallmark feature of typical bacterial pneumonia. * **Adenovirus:** Though it can cause severe bronchiolitis (and bronchiolitis obliterans), it is less common than RSV and often presents with more systemic symptoms like conjunctivitis or high fever. * **Rhinovirus:** This is the most common cause of the "common cold" (upper respiratory infection). While it can trigger asthma exacerbations in older children, it is the second most common cause of bronchiolitis, trailing behind RSV. **Clinical Pearls for NEET-PG:** * **Diagnosis:** Bronchiolitis is primarily a **clinical diagnosis**. Routine X-rays or labs are not required. * **Radiology:** Hyperinflation of lungs and flattened diaphragm are common findings. * **Management:** Treatment is mainly **supportive** (hydration and oxygenation). Routine use of bronchodilators, steroids, or antibiotics is **not** recommended. * **Prophylaxis:** **Palivizumab** (monoclonal antibody) is used for high-risk infants (e.g., prematurity, congenital heart disease).

Q: Which of the following is a sign of severe pneumonia in an 18-month-old child?

All of the above. **Explanation:** This question is based on the **WHO Integrated Management of Neonatal and Childhood Illness (IMNCI)** guidelines, which are high-yield for NEET-PG. The classification of pneumonia in children aged 2 months to 5 years is divided into two categories: **Pneumonia** and **Severe Pneumonia.** 1. **Chest Indrawing (Option A):** This is the hallmark clinical sign of **Severe Pneumonia**. It indicates significant respiratory distress where the child must use accessory muscles to breathe, causing the lower chest wall to move inward during inspiration. 2. **Stridor in a calm child (Option B):** Stridor indicates an upper airway obstruction. According to IMNCI, any child with cough or difficulty breathing who also exhibits stridor while calm is classified as having **Severe Pneumonia/Very Severe Disease**, requiring urgent hospitalization. 3. **Inability to drink (Option C):** This is one of the **General Danger Signs**. In the context of a respiratory infection, the presence of any general danger sign (inability to drink/breastfeed, lethargy, convulsions, or persistent vomiting) automatically upgrades the diagnosis to **Severe Pneumonia**. Since all three clinical findings are criteria for severe disease, **Option D** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Fast Breathing Thresholds:** * <2 months: ≥60 bpm * 2–12 months: ≥50 bpm * 12 months–5 years: ≥40 bpm * **Classification Change:** Note that the WHO updated guidelines removed the "Very Severe Disease" category for this age group; now, any child with fast breathing is "Pneumonia" (treated with oral Amoxicillin), and any child with chest indrawing or danger signs is "Severe Pneumonia" (requires IV antibiotics). * **Wheeze:** If a child has a wheeze, it should be treated with a bronchodilator before classifying the severity of pneumonia.

Q: At what age is Streptococcus pneumoniae pneumonia most commonly present?

Less than 5 years. **Explanation:** *Streptococcus pneumoniae* (Pneumococcus) is the most common bacterial cause of community-acquired pneumonia (CAP) across almost all age groups. however, its incidence is highest in children **less than 5 years of age**. **Why Option A is Correct:** In children under 5, the immune system is still developing, particularly the ability to mount a robust response to polysaccharide-encapsulated bacteria like *S. pneumoniae*. Furthermore, nasopharyngeal colonization rates are highest in this age group (up to 60-90% in some settings), serving as a reservoir for invasive disease. According to WHO and Nelson’s Pediatrics, pneumonia remains a leading cause of mortality in children under 5 globally, with *S. pneumoniae* being the primary bacterial pathogen. **Why Other Options are Incorrect:** * **Option B (5-15 years):** While *S. pneumoniae* still occurs, "atypical" pathogens like *Mycoplasma pneumoniae* and *Chlamydophila pneumoniae* become increasingly prevalent in school-aged children and adolescents. * **Options C & D (Adults):** Although *S. pneumoniae* is the most common cause of CAP in adults, the absolute incidence and the burden of disease are significantly lower compared to the vulnerable under-5 pediatric population. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of CAP:** *S. pneumoniae* is the #1 cause in children >3 weeks of age through adulthood. * **Most common cause of Neonatal Pneumonia (<3 weeks):** Group B Streptococcus (GBS) and *E. coli*. * **Radiology:** Typically presents as **lobar consolidation** with air bronchograms. * **Vaccination:** The PCV-13 (Pneumococcal Conjugate Vaccine) is part of India’s Universal Immunization Programme (UIP) to reduce mortality in the under-5 age group. * **Drug of Choice:** Amoxicillin remains the first-line treatment for pediatric pneumococcal pneumonia.

Question 1

A 5-year-old girl presents with recurrent, intermittent episodes of fever and respiratory distress over the past 1.5 years, including cough, wheezing, and dyspnea lasting for 3-4 days. Hemoptysis is present with every episode. She was diagnosed with right lower lobe pneumonia which improved with treatment. On physical examination, the patient is pale and icteric with digital clubbing. Which of the following is the most appropriate next investigation?

Accepted Answer

Bronchoalveolar lavage

Answer

Modified barium swallow study to evaluate for aspiration

Answer

Nasal swab for viral culture

Answer

Incentive spirometry

Question 2

A 2-year-old boy presents with a history of sudden onset respiratory difficulty and stridor. On auscultation, there are decreased breath sounds and wheezing on the right side. An X-ray shows a right opaque hemithorax. What is the most likely diagnosis?

Accepted Answer

Foreign body aspiration

Answer

Pneumothorax

Answer

Acute epiglottitis

Answer

Massive pleural effusion

Question 3

Pneumatoceles on chest radiographs in a child with pneumonia are most commonly associated with which organism?

Accepted Answer

Staphylococcus

Answer

Pneumococcus

Answer

Streptococcus

Answer

Hemophilus influenza

Question 4

A 9-month-old infant presents with a 2-day history of fever, cough, and breathlessness following an upper respiratory infection. The infant is febrile and has a respiratory rate of 80/min, with intercostal and subcostal retractions and extensive rhonchi on auscultation. A chest X-ray reveals a hyperinflated chest. What is the most likely diagnosis?

Accepted Answer

Bronchiolitis

Answer

Bronchial asthma

Answer

Foreign body aspiration

Answer

Bacterial pneumonia

Question 5

A 6-month-old child presents with a cough and a respiratory rate of 50 breaths per minute. What does this finding indicate?

Accepted Answer

Pneumonia

Answer

No pneumonia

Answer

Severe pneumonia

Answer

Very severe pneumonia

Question 6

A child presents with respiratory distress and a chest X-ray shows multiple air-filled spaces. What is the most likely diagnosis to be excluded from the differential diagnosis?

Accepted Answer

Congenital lobar aplasia of the lung

Answer

Congenital lung cyst

Answer

Congenital diaphragmatic hernia

Answer

Congenital adenomatoid malformation

Question 7

An 11-month-old child presents with complaints of respiratory distress. On examination, there are bilateral crepitations and wheezing. Which of the following is the most likely cause?

Accepted Answer

RSV

Answer

Pneumonia

Answer

Adenovirus

Answer

Rhinovirus

Question 8

A 2-year-old female child presented to a Primary Health Centre with a 4-day history of cough and fever, and inability to drink for the last 12 hours. On examination, the child weighed 5 kg and had a respiratory rate of 45/minute with fever. According to the WHO Integrated Management of Childhood Illness (IMCHI) classification, how would this child be classified?

Accepted Answer

Very severe disease

Answer

Pneumonia

Answer

Severe Pneumonia

Answer

No Pneumonia

Question 9

Which of the following is a sign of severe pneumonia in an 18-month-old child?

Accepted Answer

All of the above

Answer

Chest indrawing

Answer

Stridor in a calm child

Answer

Inability to drink

Question 10

At what age is Streptococcus pneumoniae pneumonia most commonly present?

Accepted Answer

Less than 5 years

Answer

5 - 15 years

Answer

20 - 25 years

Answer

30 - 40 years

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

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