MCQs on Paediatric Infections

Written by Dr. Emily Chang (MBBS, FRACP) – Paediatrician

Question 1

An 8-year-old boy is brought to the Emergency Department with right ear pain and purulent discharge since yesterday and a red swelling behind the right ear since this morning. He has the history of chronic bilateral otitis media for which he underwent bilateral grommet procedure. Which one of the following is the most appropriate next step in management?

A) Take samples for culture.
B) Hearing assessment.
C) Antibiotics.
D) CT scanning of the temporal bone.
E) Involvement of an ENT consultant.

Correct Answer: A) Take samples for culture.

Explanation:
This is a classic case of acute mastoiditis (AM), the most common suppurative complication of acute otitis media (AOM). The diagnosis is clinical, based on symptoms such as ear pain, purulent discharge, postauricular swelling, and erythema, often with a protruding auricle.

Initial management involves intravenous antibiotics, but before starting antibiotics, it is crucial to take a sample of the ear discharge for microscopy, culture, and sensitivity (MC&S) to ensure targeted treatment. If the tympanic membrane is intact, tympanocentesis or myringotomy may be performed to obtain a sample, typically done by ENT.

Option C (antibiotics) is important but should follow sample collection.
Option E (ENT involvement) is necessary but not the very first step.
Option D (CT temporal bone) is reserved for complicated or unclear cases and does not guide the immediate next step.
Option B (hearing assessment) is not appropriate in the acute setting and is generally done after resolution of infection.

Thus, the best immediate step is to take cultures before initiating treatment.

Question 2

A 6-year-old Indigenous boy presents to your practice in a rural area with purulent left ear discharge for the past 2 months. History and physical examination establish a diagnosis of chronic suppurative otitis media. Culture of the ear discharge is positive for Pseudomonas aeruginosa. After ear toileting, which one of the following is the most appropriate treatment option to consider for this child?

A) Oral Amoxicillin
B) Oral Augmentin
C) Ciprofloxacin ear drop
D) Paramycetin with steroid ear drops
E) Gentamycin ear drops

Correct Answer: C) Ciprofloxacin ear drop

Explanation:
Chronic suppurative otitis media (CSOM) is defined as middle ear infection with a perforated tympanic membrane and persistent ear discharge for over 6 weeks. It is particularly prevalent in Indigenous children and can lead to significant complications, including hearing impairment, mastoiditis, or even intracranial infections.

The most common pathogen involved in CSOM is Pseudomonas aeruginosa, a gram-negative organism. Management involves regular ear toileting to remove discharge, followed by topical antibiotic therapy.

Ciprofloxacin ear drops, a quinolone, are the treatment of choice because:

They are effective against Pseudomonas aeruginosa
They are applied directly to the site of infection
They have low ototoxicity compared to aminoglycosides

Other options are less appropriate:

A) Amoxicillin and B) Augmentin are ineffective against Pseudomonas and systemic antibiotics are not routinely recommended
D) Paramycetin (chloramphenicol) with steroids does not reliably cover Pseudomonas and steroid combinations are not routinely advised
E) Gentamycin, although previously used, is avoided due to ototoxicity risks especially in a perforated tympanic membrane

Thus, ciprofloxacin ear drops after thorough ear toileting is the most appropriate treatment.

Question 3

A 5-year-old boy is presented to your practice with headache and vomiting for the past 6 weeks. On examination, he has a temperature of 37.8°C. A non-tender lymph node is palpated in the posterior triangle of the neck. Which one of the following is the investigation to consider at this stage?

A) Blood culture
B) CT scan of the head
C) Urine culture
D) Lumbar puncture
E) Fine needle aspiration of the lymph node

Correct Answer: E) Fine needle aspiration of the lymph node

Explanation:
Lymphadenopathy in the posterior triangle of the neck is concerning for possible malignancy, especially in a child presenting with persistent symptoms (6 weeks) such as headache and vomiting, even if systemic signs are mild.

Key red flags for malignancy in cervical lymphadenopathy include:

Duration >6 weeks
Location in posterior triangle or supraclavicular region
Non-tender, hard, fixed lymph node
Associated systemic symptoms (e.g., weight loss, fever, night sweats)

In this child, the lymph node is non-tender, located in the posterior triangle, and has persisted alongside constitutional symptoms. These features warrant early investigation to exclude malignancy.

Fine needle aspiration (FNA), often guided by ultrasound, is a minimally invasive and accurate procedure to assess the nature of the lymph node. It helps differentiate between reactive, infectious, or malignant causes.

Other options:

Blood culture (A) may be helpful later if systemic infection is suspected but is not the first step here.
CT scan of the head (B) is not immediately indicated unless signs of raised intracranial pressure or focal neurological deficits are present.
Urine culture (C) is not relevant with no urinary symptoms.
Lumbar puncture (D) is inappropriate given the chronicity of symptoms and absence of classic signs of meningitis.

Therefore, the most appropriate initial investigation is fine needle aspiration of the lymph node.

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15. Paediatrics Module

15.1 Neonatology

15.2 Growth and Development

15.3 Paediatric Neurology

15.4 Paediatric Cardiology

15.5 Paediatric Respiratory

15.6 Paediatric Gastroenterology

15.7 Paediatric Nephrology

15.8 Paediatric Infections

15.9 Other Paediatric Disorders