Respiratory Diseases Practice Questions

Q: A 5-year-old girl presents with rhinorrhea, barking cough, and sore throat. Examination reveals laboured respiration. Her siblings are well. What is the most probable viral cause of her symptoms?

Parainfluenza virus. **Explanation:** The clinical presentation of a **barking cough**, rhinorrhea, and labored respiration in a young child is classic for **Croup (Laryngotracheobronchitis)**. **Why Parainfluenza virus is correct:** **Parainfluenza virus (Type 1 and 2)** is the most common cause of Croup, accounting for nearly 75% of cases. The virus causes subglottic edema and inflammation, leading to the characteristic "barking" or "brassy" cough, inspiratory stridor, and hoarseness. The prodrome of rhinorrhea and sore throat is typical of the viral upper respiratory infection that precedes the laryngeal symptoms. **Why other options are incorrect:** * **Adenovirus:** Commonly causes pharyngoconjunctival fever (sore throat, fever, and conjunctivitis) or pneumonia, but is a less frequent cause of isolated croup. * **Influenza virus:** While it can cause severe croup, it typically presents with high-grade fever, significant myalgia, and systemic toxicity. * **RSV (Respiratory Syncytial Virus):** This is the primary pathogen for **Bronchiolitis** in children under 2 years, characterized by wheezing rather than a barking cough. **Clinical Pearls for NEET-PG:** * **X-ray Finding:** The classic radiological sign for Croup is the **"Steeple Sign"** (subglottic narrowing) seen on an AP view of the neck. * **Management:** Mild cases are managed with a single dose of **Dexamethasone** (0.6 mg/kg). Severe cases with stridor at rest require **Nebulized Epinephrine** (L-epinephrine or Racemic) for rapid vasoconstriction and reduction of edema. * **Age Group:** Croup typically affects children aged 6 months to 3 years; presentation at age 5 is still common, but always rule out Epiglottitis if the child appears toxic or is drooling.

Q: Respiratory Syncytial Virus causes all of the following in children except?

Rhinosinusitis. **Explanation:** **Respiratory Syncytial Virus (RSV)** is the most significant viral pathogen of the lower respiratory tract in infants and young children. The correct answer is **Rhinosinusitis** because, while RSV commonly causes upper respiratory symptoms like rhinorrhea (the common cold), it is not a primary or typical cause of clinical rhinosinusitis in children. Rhinosinusitis is more frequently associated with bacterial pathogens (e.g., *S. pneumoniae*, *H. influenzae*) or other viruses like Rhinovirus. **Analysis of Options:** * **Bronchiolitis (Option A):** RSV is the **most common cause** of bronchiolitis worldwide. It leads to inflammation, edema, and necrosis of epithelial cells in the small airways, characterized by wheezing and air trapping. * **Croup (Option B):** While Parainfluenza type 1 is the leading cause of Laryngotracheobronchitis (Croup), RSV is a well-recognized secondary cause, especially in younger infants. * **Pneumonia (Option C):** RSV is a major cause of viral pneumonia in children under 2 years of age, often following an initial bout of bronchiolitis. **High-Yield Clinical Pearls for NEET-PG:** * **Seasonality:** RSV outbreaks typically occur in winter and early spring. * **Pathophysiology:** It causes the formation of **syncytia** (multinucleated giant cells) via its Fusion (F) protein. * **Prophylaxis:** **Palivizumab** (a monoclonal antibody against the F protein) is indicated for high-risk infants (preterm, congenital heart disease). * **Diagnosis:** Rapid antigen detection tests or PCR from nasopharyngeal swabs are the gold standards. * **Treatment:** Primarily supportive (hydration, oxygen). Ribavirin is reserved for severe cases in immunocompromised patients.

Q: An 18-month-old child presents with a history of fever and cough. On examination, the weight is 11.5 kg, respiratory rate is 46/min, and there is no chest indrawing. What is the most appropriate management?

Oral amoxicillin for 5 days and send home.. ### Explanation This question tests the clinical application of the **IMNCI (Integrated Management of Neonatal and Childhood Illness)** guidelines for the management of Acute Respiratory Infections (ARI). **1. Why Option C is Correct:** The child’s classification is **Pneumonia** (Non-severe). According to IMNCI criteria for a child aged 2 months to 5 years: * **Fast breathing** is defined as a respiratory rate (RR) $\geq$ 40/min (for ages 12 months to 5 years). * Since this 18-month-old has an **RR of 46/min** but **no chest indrawing** and no "danger signs," they are classified as having Pneumonia. * **Management:** The standard treatment for non-severe pneumonia is **Oral Amoxicillin** (40 mg/kg/day in two divided doses) for **5 days**. The child can be managed at home with instructions on supportive care and when to return. **2. Why Other Options are Incorrect:** * **Options A & B:** These are reserved for **Severe Pneumonia** or **Very Severe Disease**, characterized by chest indrawing or "General Danger Signs" (inability to drink/breastfeed, persistent vomiting, lethargy/unconsciousness, or convulsions). This child does not meet these criteria. * **Option D:** Home remedies (like soothing the throat with honey) are indicated for "No Pneumonia" (Cough/Cold), where the RR is < 40/min and no indrawing is present. **3. High-Yield Clinical Pearls for NEET-PG:** * **Cut-off for Fast Breathing:** * < 2 months: $\geq$ 60/min * 2–12 months: $\geq$ 50/min * 12 months–5 years: $\geq$ 40/min * **Drug of Choice:** Oral Amoxicillin has replaced Cotrimoxazole as the first-line drug for pneumonia in the revised IMNCI guidelines. * **Follow-up:** A child treated for pneumonia at home must be reassessed after **2 days** (48 hours).

Q: A 20-day-old neonate presents with non-passage of meconium, rectal prolapse, poor growth, and delayed maturation. The neonate has been hospitalized for 10 days due to a respiratory tract infection. On examination, increased anteroposterior diameter of the chest, generalized hyperresonance, scattered coarse crackles, digital clubbing, a protuberant abdomen, and decreased muscle mass are noted. X-ray and USG of the abdomen were performed. Which of the following drugs can be used in the treatment of the disease suggested by these findings, except?

None of the above. ### **Explanation** The clinical presentation of delayed meconium passage, rectal prolapse, failure to thrive (poor growth/decreased muscle mass), and recurrent respiratory infections (increased AP diameter, crackles, clubbing) in a neonate is a classic description of **Cystic Fibrosis (CF)**. **1. Why the Correct Answer is "None of the above":** The question asks which drug **cannot** be used (except) for the treatment of CF. However, all the listed options (A, B, and C) are established components of CF management. Therefore, "None of the above" is the correct choice because all three drugs are actually used in treatment. **2. Analysis of Options:** * **Ivacaftor (Option A):** A CFTR potentiator that improves the function of the defective chloride channel. It is specifically used for patients with "gating" mutations (like G551D). * **Dornase alpha (Option B):** A recombinant human DNase that breaks down extracellular DNA in the thick mucus of CF patients, reducing sputum viscosity and improving lung function. * **Mannitol (Option C):** Inhaled hypertonic mannitol acts as an osmotic agent that draws water into the airway surface liquid, facilitating mucociliary clearance. **3. Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Sweat Chloride Test (Value >60 mEq/L). * **Most Common Mutation:** ΔF508 (Class II mutation - protein misfolding). * **Gastrointestinal Hallmark:** Meconium ileus (earliest manifestation) and Pancreatic Insufficiency (leading to steatorrhea and fat-soluble vitamin deficiency). * **Radiology:** "Finger-in-glove" appearance due to mucoid impaction. * **Microbiology:** *Staphylococcus aureus* is the most common pathogen in early childhood; *Pseudomonas aeruginosa* becomes dominant in older children/adults.

Q: Which one of the following causes Pectus carinatum?

Childhood asthma. **Explanation:** **Pectus carinatum** (pigeon chest) is a chest wall deformity characterized by the outward protrusion of the sternum and ribs. **Why Childhood Asthma is correct:** Chronic, severe childhood asthma leads to recurrent airway obstruction and hyperinflation of the lungs. During growth, the persistent increased work of breathing and the use of accessory muscles exert chronic outward pressure on the developing, pliable thoracic cage. This mechanical stress results in the permanent outward bowing of the sternum. In contrast, **Pectus excavatum** (funnel chest) is often associated with conditions like Marfan syndrome or rickets. **Analysis of Incorrect Options:** * **Pulmonary Emphysema:** While emphysema causes a **"Barrel Chest"** (increased anteroposterior diameter due to air trapping), it is typically a disease of adults. Pectus carinatum specifically refers to a structural deformity occurring during the developmental years of the skeletal system. * **Atelectasis:** This involves lung collapse, which leads to a *decrease* in thoracic volume. If chronic and unilateral, it may cause a flattening or indrawing of the chest wall on the affected side, not a protrusion. * **Lobar Pneumonia:** This is an acute infectious process. Structural bony deformities like pectus carinatum require chronic, long-term mechanical stress and do not result from short-term inflammatory conditions. **High-Yield Clinical Pearls for NEET-PG:** * **Harrison’s Sulcus:** A horizontal groove along the lower border of the thorax (at the insertion of the diaphragm), often seen in children with chronic asthma or rickets. * **Barrel Chest:** Characteristic of COPD/Emphysema (Ratio of AP to Transverse diameter becomes 1:1). * **Rachitic Rosary:** Knobby deformities at the costochondral junctions, pathognomonic for Rickets.

Q: The first child of a normal couple was diagnosed to have cystic fibrosis. What is the percentage of the chances for the second child to be affected?

25%. **Explanation:** **1. Why Option C is correct:** Cystic Fibrosis (CF) is an **Autosomal Recessive (AR)** disorder caused by mutations in the CFTR gene. In this scenario, since the couple is "normal" (phenotypically healthy) but has an affected child, both parents must be **obligate carriers** (Heterozygous, Aa). According to Mendelian genetics, a cross between two carriers (Aa x Aa) results in: * 25% chance of being affected (aa) * 50% chance of being a carrier (Aa) * 25% chance of being genetically normal (AA) Therefore, for every subsequent pregnancy, there is a **1 in 4 (25%)** chance of the child being affected. **2. Why other options are incorrect:** * **Option A (50%):** This would be the risk if one parent was affected (aa) and the other was a carrier (Aa), or in Autosomal Dominant conditions where one parent is affected. * **Option B (0%):** This is incorrect because both parents carry the recessive allele; the risk is never zero in subsequent pregnancies. * **Option D (100%):** This would only occur if both parents were affected by the disease (aa x aa). **Clinical Pearls for NEET-PG:** * **Most common mutation in CF:** ΔF508 (Class II defect - protein misfolding). * **Gold Standard Diagnosis:** Sweat Chloride Test (Value >60 mEq/L is diagnostic). * **Common presentation:** Recurrent pneumonia, pancreatic insufficiency, and meconium ileus (earliest manifestation). * **Other AR disorders to remember:** Sickle Cell Anemia, Thalassemia, Phenylketonuria, and Wilson’s Disease. * **Recurrence Risk:** In AR disorders, the risk remains 25% for *each* pregnancy, regardless of the outcome of previous siblings.

Q: An 18-month-old child presents with low-grade fever, stridor, and barking cough. A chest X-ray was taken. What is the line of treatment?

Single dose of dexamethasone. **Explanation:** The clinical presentation of low-grade fever, barking cough, and inspiratory stridor in an 18-month-old is classic for **Croup (Laryngotracheobronchitis)**, most commonly caused by the Parainfluenza virus. The characteristic X-ray finding (implied) is the **"Steeple Sign,"** representing subglottic narrowing. **Why Dexamethasone is correct:** Corticosteroids are the mainstay of treatment for Croup. A **single dose of Dexamethasone** (0.15 mg/kg to 0.6 mg/kg, orally or parenterally) reduces laryngeal mucosal edema. It has been shown to decrease the severity of symptoms, reduce the need for hospitalization, and shorten the duration of stay. In moderate to severe cases, nebulized L-epinephrine is added for rapid symptomatic relief. **Why other options are incorrect:** * **A. Third-generation cephalosporins:** These are used for **Acute Epiglottitis** (caused by *H. influenzae*), which presents with high fever, drooling, and a "Thumb sign" on X-ray. Croup is viral and does not require antibiotics. * **B. Heimlich's maneuver:** This is the emergency management for **Foreign Body Aspiration**, which typically presents with sudden-onset choking and unilateral wheezing, not a prodromal fever. * **C. Reassurance:** While mild croup can be managed at home, "reassurance" alone is insufficient as Dexamethasone is now recommended for even mild cases to prevent progression. **NEET-PG High-Yield Pearls:** * **Most common cause:** Parainfluenza virus Type 1. * **X-ray Sign:** Steeple sign (Subglottic narrowing) on AP view. * **Age group:** 6 months to 3 years. * **Scoring system:** Westley Croup Score is used to assess severity. * **Key differentiator:** Epiglottitis has a "cherry-red epiglottis" and no barking cough; Croup has a barking cough and subglottic edema.

Question 1

A 5-year-old girl presents with rhinorrhea, barking cough, and sore throat. Examination reveals laboured respiration. Her siblings are well. What is the most probable viral cause of her symptoms?

Accepted Answer

Parainfluenza virus

Answer

Adenovirus

Answer

Influenza virus

Answer

RSV

Question 2

A 2-year-old female child presented with fever, cough, and respiratory distress. Chest X-ray showed consolidation in the right lower lobe. She improved with antibiotics, but on follow-up at 8 weeks, she was found to have increasing consolidation in the right lower lobe and recurrent fever. What would be your next investigation?

Accepted Answer

Bronchoscopy

Answer

Bacterial culture of the nasopharynx

Answer

CT scan of the chest

Answer

Allergen sensitivity test

Question 3

Respiratory Syncytial Virus causes all of the following in children except?

Accepted Answer

Rhinosinusitis

Answer

Bronchiolitis

Answer

Croup

Answer

Pneumonia

Question 4

An 18-month-old child presents with a history of fever and cough. On examination, the weight is 11.5 kg, respiratory rate is 46/min, and there is no chest indrawing. What is the most appropriate management?

Accepted Answer

Oral amoxicillin for 5 days and send home.

Answer

Intravenous antibiotics at the PHC and observe.

Answer

Give the first dose of intravenous antibiotics and refer to a higher center.

Answer

Home remedies.

Question 5

A 20-day-old neonate presents with non-passage of meconium, rectal prolapse, poor growth, and delayed maturation. The neonate has been hospitalized for 10 days due to a respiratory tract infection. On examination, increased anteroposterior diameter of the chest, generalized hyperresonance, scattered coarse crackles, digital clubbing, a protuberant abdomen, and decreased muscle mass are noted. X-ray and USG of the abdomen were performed. Which of the following drugs can be used in the treatment of the disease suggested by these findings, except?

Accepted Answer

None of the above

Answer

Ivacaftor

Answer

Dornase alpha (Pulmozyme)

Answer

Mannitol

Question 6

Which one of the following causes Pectus carinatum?

Accepted Answer

Childhood asthma

Answer

Pulmonary emphysema

Answer

Atelectasis

Answer

Lobar pneumonia

Question 7

Which organism most commonly causes bronchitis in children?

Accepted Answer

Haemophilus influenzae

Answer

Respiratory Syncytial Virus (RSV)

Answer

Mycoplasma pneumoniae

Answer

Epstein-Barr Virus (EBV)

Question 8

The first child of a normal couple was diagnosed to have cystic fibrosis. What is the percentage of the chances for the second child to be affected?

Accepted Answer

25%

Answer

50%

Answer

0%

Answer

100%

Question 9

An 18-month-old child presents with low-grade fever, stridor, and barking cough. A chest X-ray was taken. What is the line of treatment?

Accepted Answer

Single dose of dexamethasone

Answer

Third-generation cephalosporins

Answer

Heimlich's maneuver

Answer

Reassurance

Question 10

What is the preferred inhalation method for a 3-year-old child with bronchial asthma?

Accepted Answer

Metered Dose Inhaler (MDI) with a spacer and a face mask

Answer

Metered Dose Inhaler (MDI) with a spacer

Answer

Metered Dose Inhaler (MDI) directly

Answer

Rotary capsule (Rotacap)

Respiratory Diseases — MCQs

Respiratory Diseases — MCQs

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