Lower Respiratory Tract Infections — MCQs

10 questions

True regarding the presentation of primary tuberculosis is

A 6-month-old female infant is brought to the physician with a 2-day history of severe cough, wheezing, and respiratory distress. Physical examination shows rhinitis, mild cyanosis, and fever. Which of the following is the most likely etiology of this child's pulmonary infection?

A 3 month old infant presents with a 3 day history of fever, cough, and poor feeding. On examination, the baby appears ill and has a temperature of 102 F and a respiratory rate of 32. A chest x-ray film showed bilateral patchy infiltrates in the lungs. Which of the following is the most likely etiologic agent?

A 14-year-old boy presents with headache, fever, and cough for 2 days. Sputum is scant and non-purulent and gram stain reveals many white cells but no organisms. The treatment should be initiated with :

Which statement is FALSE about '100 Day Cough'?

Most dangerous sign in lower respiratory tract infection (LRTI) in children is:

A 2-month-old child with a birth weight of 2 kg presents with poor feeding, excessive sleepiness, and wheezing. What is the most likely diagnosis?

Which of the following is not associated with primary ciliary dyskinesia?

Which of the following conditions is most associated with digital clubbing in children?

Q10

A 24 month child, with a weight of 11 kg, has RR of 38 / min, chest indrawing, cough and fever. Management according to IMNCI?

Lower Respiratory Tract Infections Indian Medical PG Practice Questions and MCQs

Question 1: True regarding the presentation of primary tuberculosis is

A. B/L pleural effusion with negative Tuberculin test
B. U/L hilar lymphadenopathy (Correct Answer)
C. Sustained chronic pyrexia
D. B/L pleural effusion with positive tuberculin test

Explanation: ***U/L hilar lymphadenopathy*** - A **unilateral hilar lymphadenopathy** is a classic radiographic finding in **primary pulmonary tuberculosis** in children and often in adults, representing the enlargement of lymph nodes draining the primary lung lesion. - The disease typically begins with a primary lesion (Ghon focus) in the lung parenchyma and regional **lymph node involvement** constitutes the primary complex [1]. *B/L pleural effusion with negative Tuberculin test* - **Bilateral pleural effusion** is an uncommon presentation for primary tuberculosis; typically, effusions are unilateral. - A **negative Tuberculin test** (PPD) would make a diagnosis of tuberculosis less likely, although it can be negative in immunocompromised individuals or in the very early stages of infection. *Sustained chronic pyrexia* - While fever (pyrexia) is a common symptom of tuberculosis, **sustained chronic pyrexia** is more characteristic of secondary (post-primary) or disseminated tuberculosis, not necessarily primary infection which is often asymptomatic or mildly symptomatic [2]. - Fevers in primary TB, if present, can be low-grade and intermittent rather than sustained and chronic. *B/L pleural effusion with positive tuberculin test* - Although a **positive Tuberculin test** indicates prior exposure to M. tuberculosis, **bilateral pleural effusion** is an unusual initial presentation of primary tuberculosis. - Pleural effusions in TB are typically unilateral and usually result from a hypersensitivity reaction or direct spread from a primary lesion, but bilateral involvement is less common.

Question 2: A 6-month-old female infant is brought to the physician with a 2-day history of severe cough, wheezing, and respiratory distress. Physical examination shows rhinitis, mild cyanosis, and fever. Which of the following is the most likely etiology of this child's pulmonary infection?

A. Respiratory syncytial virus (Correct Answer)
B. Cytomegalovirus
C. Parainfluenza virus
D. Adenovirus

Explanation: ***Respiratory syncytial virus*** - **Respiratory syncytial virus (RSV)** is the most common cause of **bronchiolitis** in infants and young children, characterized by cough, wheezing, and respiratory distress. - The age of the patient (6-month-old infant) and the clinical presentation, including rhinitis, cyanosis, and fever, are highly consistent with an RSV infection. *Cytomegalovirus* - **Cytomegalovirus (CMV)** infection primarily affects immunocompromised individuals or can cause congenital infections. - While CMV can cause respiratory symptoms, it typically manifests as **pneumonitis** in infants, often without the prominent wheezing seen in this case. *Parainfluenza virus* - **Parainfluenza virus (PIV)** is a common cause of **croup** (laryngotracheobronchitis) in infants and young children, characterized by a barking cough and stridor. - While PIV can rarely cause bronchiolitis, the typical presentation described, especially with prominent wheezing, is less characteristic of PIV compared to RSV. *Adenovirus* - **Adenovirus** can cause a variety of respiratory illnesses, including pneumonia, bronchitis, and pharyngitis. - While adenovirus can cause severe respiratory infections in infants, RSV is more frequently associated with the specific constellation of severe cough, wheezing, and respiratory distress in this age group.

Question 3: A 3 month old infant presents with a 3 day history of fever, cough, and poor feeding. On examination, the baby appears ill and has a temperature of 102 F and a respiratory rate of 32. A chest x-ray film showed bilateral patchy infiltrates in the lungs. Which of the following is the most likely etiologic agent?

A. Parainfluenza type 1
B. Influenza type A
C. Respiratory syncytial virus (Correct Answer)
D. Coronavirus

Explanation: ***Respiratory syncytial virus*** - **Respiratory syncytial virus (RSV)** is the most common cause of **bronchiolitis** and **pneumonia** in infants, particularly those under 6 months. - The presentation of fever, cough, poor feeding, respiratory distress (high respiratory rate), and bilateral patchy infiltrates on chest X-ray are highly characteristic of severe RSV infection in a **3-month-old infant**. *Parainfluenza type 1* - **Parainfluenza type 1 (PIV-1)** is primarily associated with **croup** (laryngotracheobronchitis) in infants and young children, characterized by a **barking cough** and stridor. - While it can cause lower respiratory tract infections, severe pneumonia with bilateral patchy infiltrates and prominent respiratory distress is less typical than with RSV. *Influenza type A* - **Influenza type A** can cause severe respiratory illness in infants, but it is typically more common in older children and adults. - While it can present with fever, cough, and pneumonia, RSV is a more frequent cause of severe lower respiratory tract disease in this specific age group (**3-month-old infant**). *Coronavirus* - While some coronaviruses (e.g., **SARS-CoV-2**) can cause severe respiratory illness in infants, they are generally less common causes of typical infant bronchiolitis or pneumonia compared to RSV. - The pattern of a 3-month-old with fever, cough, respiratory distress, and patchy infiltrates is most strongly associated with RSV in the absence of specific epidemiological factors pointing to another coronavirus.

Question 4: A 14-year-old boy presents with headache, fever, and cough for 2 days. Sputum is scant and non-purulent and gram stain reveals many white cells but no organisms. The treatment should be initiated with :

A. Azithromycin (Correct Answer)
B. Levofloxacin
C. Amikacin
D. Cefazolin

Explanation: ***Azithromycin*** - The clinical picture of **headache, fever, cough, scant non-purulent sputum**, and Gram stain showing white cells but no organisms is highly suggestive of **atypical pneumonia**, likely caused by *Mycoplasma pneumoniae* in this age group. - **Macrolides** like azithromycin are the **first-line treatment** for atypical pneumonia as they are effective against organisms like *Mycoplasma* and *Chlamydia* which lack cell walls and are therefore resistant to beta-lactam antibiotics. *Levofloxacin* - **Levofloxacin** is a **fluoroquinolone**, which is effective against atypical pathogens but is generally reserved for **older patients** or those with **allergies** to macrolides due to concerns about potential side effects like cartilage damage in children. - Using fluoroquinolones as a first-line treatment in adolescents for suspected atypical pneumonia is **not recommended** due to these potential side effects and the availability of safer alternatives. *Amikacin* - **Amikacin** is an **aminoglycoside antibiotic** primarily used for severe infections caused by **Gram-negative bacteria**. - It is **ineffective against atypical bacteria** like *Mycoplasma* or *Chlamydia* which are the likely causative agents in this scenario. *Cefazolin* - **Cefazolin** is a **first-generation cephalosporin**, which is a **beta-lactam antibiotic** effective mostly against Gram-positive cocci and some Gram-negative bacteria. - It is **ineffective against atypical pathogens** because these organisms **lack a cell wall** (like *Mycoplasma*) or have cell walls that are not targeted by beta-lactam antibiotics.

Question 5: Which statement is FALSE about '100 Day Cough'?

A. Incubation period is 7-14 days.
B. Erythromycin is the drug of choice.
C. There is no subclinical or chronic carrier state.
D. Incidence and fatality are more common in males than females. (Correct Answer)

Explanation: ***Incidence and fatality are more common in males than females.*** - This statement is **false** as written as a general statement, though the evidence is nuanced. In **infants**, particularly those under 6 months, **male sex is actually a recognized risk factor** for severe pertussis and higher mortality. However, in older age groups and for overall disease incidence (including milder cases), the sex distribution is more equal or may vary by region. - The statement is marked false because it presents an overly broad generalization. **Severe disease and fatality** in the most vulnerable population (young infants) actually shows **male predominance**, but mild/moderate disease across all ages doesn't consistently show this pattern. - Current epidemiological data shows **case fatality rates are higher in male infants**, attributed to smaller airways and immunological differences. *Incubation period is 7-14 days.* - This statement is **true**. The incubation period for **pertussis** (100-day cough) is typically **7 to 10 days**, with a range of 6 to 20 days. - This is the period when *Bordetella pertussis* multiplies in the respiratory tract before symptomatic illness begins. *Erythromycin is the drug of choice.* - This statement is **true**. **Macrolide antibiotics** including erythromycin, azithromycin, and clarithromycin are the **drugs of choice** for treating pertussis. - Most effective when given during the **catarrhal stage** (first 1-2 weeks) to reduce symptom severity and transmission. Also used for post-exposure prophylaxis in contacts. - **Azithromycin** is now often preferred over erythromycin due to better tolerability and shorter course. *There is no subclinical or chronic carrier state.* - This statement is **true**. **Pertussis does not establish a chronic carrier state**. Unlike some bacterial infections, *Bordetella pertussis* does not persist asymptomatically long-term. - Infected individuals typically develop symptomatic disease, though symptoms may be mild or atypical in vaccinated individuals or adults. - Once the infection clears (with or without treatment), the organism is eliminated and does not persist.

Question 6: Most dangerous sign in lower respiratory tract infection (LRTI) in children is:

A. Chest retraction
B. Grunting (Correct Answer)
C. Tachypnea
D. Abdominal breathing

Explanation: ***Grunting*** - **Grunting** is an expiratory sound produced by partial closure of the glottis to maintain positive end-expiratory pressure (PEEP), indicating **severe respiratory distress** and **impending respiratory failure**. - This compensatory mechanism suggests significant **alveolar collapse** or **pulmonary edema** and is a **critical danger sign** requiring immediate intervention in children with LRTI. - According to WHO and IMNCI guidelines, grunting is classified as a **danger sign** warranting urgent referral and management. *Incorrect: Chest retraction* - **Chest retractions** occur when the intercostal muscles, suprasternal, or subcostal areas pull inward during inspiration due to increased negative intrathoracic pressure. - Although it is a sign of respiratory distress indicating increased work of breathing, it is less dire than grunting, which signifies a more critical phase of respiratory failure. *Incorrect: Tachypnea* - **Tachypnea** (increased respiratory rate) is an early and common sign of LRTI in children, as the body attempts to compensate for hypoxemia or increased metabolic demand. - While concerning, it is often an initial response and, by itself, is not as immediately life-threatening as grunting, which suggests severe impairment of gas exchange. *Incorrect: Abdominal breathing* - **Abdominal breathing** (or diaphragmatic breathing) is a normal compensatory mechanism in infants and young children during respiratory distress. - While it indicates increased work of breathing, it is not as dangerous as grunting, which signifies a more advanced stage of respiratory compromise.

Question 7: A 2-month-old child with a birth weight of 2 kg presents with poor feeding, excessive sleepiness, and wheezing. What is the most likely diagnosis?

A. Viral upper respiratory tract infection
B. Severe pneumonia
C. Bronchiolitis (Correct Answer)
D. Congestive heart failure

Explanation: ***Bronchiolitis*** - This presentation in a 2-month-old, especially with a history of **low birth weight**, points to bronchiolitis, characterized by **poor feeding**, **excessive sleepiness**, and **wheezing**. - **Bronchiolitis** primarily affects infants under 2 years (peak 2-6 months) and presents with signs of **lower respiratory tract involvement** including wheezing, tachypnea, and respiratory distress, which can lead to fatigue and feeding difficulties. - The **wheezing** is the key distinguishing feature indicating **small airway inflammation** typical of bronchiolitis. *Incorrect: Viral upper respiratory tract infection* - While viral URTI can cause nasal congestion and rhinorrhea, it typically affects the **upper airways** (nose, pharynx). - **Wheezing** indicates **lower airway involvement**, making bronchiolitis more likely than simple URTI. - The combination of systemic symptoms (poor feeding, excessive sleepiness) with wheezing suggests more significant lower respiratory disease. *Incorrect: Severe pneumonia* - Though severe pneumonia can cause similar systemic symptoms, **crackles or rales** are more characteristic than **wheezing**. - Pneumonia typically presents with **fever**, **cough**, and **focal consolidation** on examination. - The predominant **wheezing** in this case points more toward bronchiolitis with its diffuse small airway involvement. *Incorrect: Congestive heart failure* - CHF is an important differential in low birth weight infants with poor feeding and respiratory distress. - However, CHF typically presents with **tachycardia**, **hepatomegaly**, **gallop rhythm**, and **bilateral crackles** rather than prominent wheezing. - The **wheezing** without cardiac signs makes bronchiolitis more likely than a primary cardiac cause.

Question 8: Which of the following is not associated with primary ciliary dyskinesia?

A. Sinusitis
B. Respiratory infection
C. Sterility in males
D. Hypothyroidism (Correct Answer)

Explanation: ***Hypothyroidism*** - **Hypothyroidism** is a condition related to the thyroid gland's function and is **not directly associated** with defects in ciliary structure or function. - While other systemic conditions can coexist, there is no known mechanistic link between primary ciliary dyskinesia and thyroid dysfunction. *Sterility in males* - **Sterility in males** is a common manifestation of primary ciliary dyskinesia, as the abnormal cilia impair **sperm motility**, preventing effective fertilization. - The **flagellum of sperm** shares structural similarities with cilia, and its dysfunction leads to **immotile spermatozoa**. *Sinusitis* - **Sinusitis** is a hallmark symptom of primary ciliary dyskinesia due to impaired ciliary clearance in the **paranasal sinuses**. - The inability to effectively clear mucus leads to chronic and recurrent **sinus infections** and inflammation. *Respiratory infection* - **Recurrent respiratory infections**, including bronchitis, pneumonia, and bronchiectasis, are characteristic features of primary ciliary dyskinesia. - Defective ciliary action in the **respiratory tract** prevents proper clearance of mucus and pathogens, leading to chronic infections.

Question 9: Which of the following conditions is most associated with digital clubbing in children?

A. Croup
B. Bronchiolitis
C. Asthma
D. Cystic fibrosis (Correct Answer)

Explanation: ***Cystic fibrosis*** - **Cystic fibrosis** is a common cause of **digital clubbing** in children due to chronic hypoxemia and lung disease, leading to abnormal growth of connective tissue at the nail beds. - The chronic lung infections, bronchiectasis, and airway obstruction characteristic of cystic fibrosis contribute to persistent **tissue hypoxia**, which is a primary driver of clubbing. *Croup* - Croup is an acute viral infection of the upper airway, primarily characterized by a **barking cough** and **stridor**, and generally resolves within a week without chronic complications like clubbing. - It does not cause chronic hypoxemia necessary for the development of digital clubbing. *Bronchiolitis* - **Bronchiolitis** is an acute viral infection of the lower respiratory tract, most common in infants, causing wheezing and respiratory distress, but it is typically a **short-lived illness** without chronic sequelae leading to clubbing. - This condition does not cause prolonged enough or severe enough **hypoxia** to result in clubbing. *Asthma* - While severe, uncontrolled **asthma** can cause intermittent hypoxia, it is typically not associated with chronic digital clubbing, especially in children, unless there are other coincident chronic lung conditions. - Digital clubbing is rare in asthma and often suggests an alternate or co-existing pathology, such as **bronchiectasis** or **cystic fibrosis**.

Question 10: A 24 month child, with a weight of 11 kg, has RR of 38 / min, chest indrawing, cough and fever. Management according to IMNCI?

A. Refer to a higher-level health facility for further management.
B. Monitor at home without medical treatment.
C. Give antibiotics (Correct Answer)
D. Provide symptomatic treatment with antipyretics only.

Explanation: ***Give antibiotics*** - The child presents with **chest indrawing** along with cough and fever, which according to **IMNCI guidelines** classifies as **pneumonia**. - Note: RR of 38/min is **within normal limits** for a 24-month-old child (fast breathing threshold is ≥40/min for 12-59 months age group). - The diagnosis of pneumonia is based on the presence of **chest indrawing**, not fast breathing in this case. - According to **IMNCI**, pneumonia (without danger signs) should be treated with **oral antibiotics** (amoxicillin 250 mg twice daily for 5 days) at the primary care level. - The child should be followed up in 2 days and the mother advised on when to return immediately. *Refer to a higher-level health facility for further management.* - Referral is indicated for **severe pneumonia**, which requires presence of any **general danger sign** (inability to drink/breastfeed, persistent vomiting, convulsions, lethargy/unconsciousness, or stridor in calm child). - This child has **pneumonia** (not severe), so outpatient treatment with oral antibiotics is appropriate. *Monitor at home without medical treatment.* - This would be inappropriate as the child has **pneumonia** requiring antibiotic treatment. - Untreated pneumonia can rapidly progress to severe disease and is a **leading cause of child mortality** in developing countries. *Provide symptomatic treatment with antipyretics only.* - While antipyretics (paracetamol) can be given for fever, they do not treat the underlying **bacterial infection**. - Antibiotics are essential to treat pneumonia and prevent complications and mortality.

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