Respiratory Diseases Practice Questions

Q: A 1-month-old infant presents with cough and sneezing, a respiratory rate of 40 per minute, and no chest indrawing. What is the most appropriate management?

Frequent breastfeeding. This question tests your ability to classify and manage acute respiratory infections (ARI) in young infants based on the **IMNCI (Integrated Management of Neonatal and Childhood Illness)** guidelines. ### **Explanation** According to IMNCI guidelines, a child aged **0–2 months** with a cough and cold is evaluated based on respiratory rate and signs of distress. * **Normal Respiratory Rate:** In an infant <2 months, a rate of **<60 breaths per minute** is considered normal. * **Signs of Severity:** The absence of fast breathing (≥60 bpm), chest indrawing, or "danger signs" (lethargy, convulsions, persistent vomiting, or inability to feed) classifies this case as **"No Pneumonia: Cough or Cold."** For "No Pneumonia," the management is supportive. **Frequent breastfeeding** is the priority to prevent dehydration, provide immunological support, and soothe the throat. Mothers are advised to keep the nose clear and return if symptoms worsen. ### **Why Other Options are Incorrect** * **A & B (Urgent referral/IV antibiotics):** These are indicated for "Very Severe Disease" (e.g., chest indrawing, grunting, or danger signs). This infant is hemodynamically stable with a normal respiratory rate. * **D (Oral antibiotic syrup):** Antibiotics are indicated for "Pneumonia" (fast breathing). Since this infant's rate is 40 bpm (normal), antibiotics are unnecessary and contribute to resistance. ### **High-Yield Clinical Pearls for NEET-PG** * **IMNCI Cut-offs for Fast Breathing:** * <2 months: ≥60 bpm * 2–12 months: ≥50 bpm * 12 months–5 years: ≥40 bpm * **Chest Indrawing:** In infants <2 months, mild chest indrawing is common; only **severe** chest indrawing is a sign of serious illness. * **Key Management:** For simple cough/cold, avoid over-the-counter cough suppressants in infants; focus on hydration and warmth.

Q: What is the recommended treatment for chlamydial pneumonia?

Erythromycin. **Explanation:** **Chlamydial pneumonia** (caused by *Chlamydia trachomatis*) typically presents in infants aged 1–3 months with a characteristic "staccato cough," tachypnea, and hyperinflation on X-ray, often preceded by neonatal conjunctivitis. **1. Why Erythromycin is Correct:** *Chlamydia trachomatis* is an obligate intracellular bacterium, meaning it lacks a traditional peptidoglycan cell wall. Therefore, it is highly susceptible to **Macrolides**, which inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit. **Erythromycin** (50 mg/kg/day for 14 days) is the traditional drug of choice. It effectively clears the nasopharyngeal carriage and treats the pneumonia. **2. Why the Other Options are Incorrect:** * **Ceftriaxone (B) and Penicillin (C):** These are Beta-lactam antibiotics that act by inhibiting cell wall synthesis. Since *Chlamydia* lacks a typical cell wall, these drugs are entirely ineffective. * **Sulphonamide (D):** While some older texts mention sulfonamides for certain chlamydial infections, they are not the first-line treatment for pneumonia in infants due to the risk of kernicterus and lower efficacy compared to macrolides. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Triad:** Afebrile illness + Staccato cough + Peripheral eosinophilia (≥400 cells/mm³). * **Association:** About 50% of infants with chlamydial pneumonia have a history of neonatal conjunctivitis (inclusion blennorrhea). * **Alternative:** Azithromycin is increasingly used due to a shorter course and better GI tolerance. * **Caution:** Systemic Erythromycin in infants <2 weeks old is associated with an increased risk of **Infantile Hypertrophic Pyloric Stenosis (IHPS)**; patients should be monitored for symptoms of projectile vomiting.

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).

Question 1

A 1-month-old infant presents with cough and sneezing, a respiratory rate of 40 per minute, and no chest indrawing. What is the most appropriate management?

Accepted Answer

Frequent breastfeeding

Answer

Urgent referral to hospital

Answer

Intravenous antibiotics

Answer

Oral antibiotic syrup

Question 2

A 6-year-old boy presented with recurrent chest infections. Sweat chloride test showed raised values. What is the next best investigation to confirm the diagnosis?

Accepted Answer

Nasal electrode potential difference

Answer

72-hour fecal fat estimation

Answer

CT chest

Answer

DNA analysis of delta F-508 mutation

Question 3

What is the recommended treatment for chlamydial pneumonia?

Accepted Answer

Erythromycin

Answer

Ceftriaxone

Answer

Penicillin

Answer

Sulphonamide

Question 4

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 5

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 6

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 7

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 8

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 9

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 10

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

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

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