Pneumonia
Why is this topic important?
Pneumonia is one of the commonest serious childhood infections worldwide and remains a major cause of morbidity and mortality in children.
It is a very high-yield MRCPCH topic because candidates are expected to:
Recognise the clinical presentation
Differentiate viral and bacterial pneumonia
Identify severe disease
Understand investigation and management principles
Recognise complications
Interpret common examination and radiological findings
Pneumonia frequently appears in MRCPCH clinical scenarios, particularly in children presenting with fever, cough and respiratory distress.
Definition
Pneumonia is an infection of the lung parenchyma resulting in inflammation of the alveoli and surrounding lung tissue.
It may be caused by:
Viruses
Bacteria
Fungi (rare in immunocompetent children)
Atypical organisms
The severity ranges from mild community-acquired infection to life-threatening respiratory failure.
Key MRCPCH Facts
Pneumonia is a common cause of childhood hospital admission.
Viral pneumonia is more common in younger children.
Bacterial pneumonia becomes increasingly common with age.
Tachypnoea is one of the most important clinical signs.
Chest X-ray is not routinely required in uncomplicated cases.
Hypoxia is an important marker of severity.
Pleural effusion and empyema are important complications.
Pathophysiology
Infection Reaches the Lung
Organisms enter the lower respiratory tract via:
Inhalation
Aspiration
Haematogenous spread (rare)
Inflammatory Response
The immune system responds with:
Recruitment of inflammatory cells
Increased capillary permeability
Alveolar fluid accumulation
Consequences
This results in:
Reduced gas exchange
Ventilation-perfusion mismatch
Hypoxaemia
Increased work of breathing
Classification
Community-Acquired Pneumonia (CAP)
Develops outside hospital.
Most common form seen in children.
Hospital-Acquired Pneumonia
Develops after hospital admission.
Often associated with different pathogens.
Aspiration Pneumonia
Occurs following aspiration of gastric contents or foreign material.
Common Organisms
Viral Causes
Most common in infants and preschool children:
Respiratory Syncytial Virus (RSV)
Influenza virus
Parainfluenza virus
Adenovirus
Human metapneumovirus
Bacterial Causes
Most common:
Streptococcus pneumoniae
Other causes:
Staphylococcus aureus
Group A Streptococcus
Haemophilus influenzae
Atypical Causes
More common in older children:
Mycoplasma pneumoniae
Chlamydia pneumoniae
Risk Factors
Child Factors
Prematurity
Chronic lung disease
Congenital heart disease
Neuromuscular disorders
Immunodeficiency
Environmental Factors
Tobacco smoke exposure
Overcrowding
Poor vaccination status
Medical Factors
Aspiration risk
Chronic illness
Clinical Features
Typical Symptoms
Fever
Cough
Breathlessness
Reduced feeding
Lethargy
Respiratory Signs
Tachypnoea
Increased work of breathing
Nasal flaring
Recession
Grunting
Examination Findings
Crackles
Reduced air entry
Bronchial breathing
Dullness to percussion (sometimes)
Assessing Severity
Mild Disease
Feeding well
No hypoxia
Mild respiratory symptoms
Moderate Disease
Significant tachypnoea
Increased work of breathing
Reduced oral intake
Severe Disease
Oxygen saturation reduced
Marked respiratory distress
Apnoea
Cyanosis
Exhaustion
Requires urgent assessment and treatment.
Differential Diagnosis
Respiratory
Bronchiolitis
Asthma
Croup
Foreign body aspiration
Cardiac
Heart failure
Congenital heart disease
Other
Pleural effusion
Pulmonary oedema
Investigations
Clinical Diagnosis
Most children with uncomplicated pneumonia do not require extensive investigations.
Pulse Oximetry
Essential to assess oxygenation.
Blood Tests
May include:
Full blood count
CRP
Blood culture (selected cases)
Chest X-Ray
Not routinely required in uncomplicated community-acquired pneumonia.
May demonstrate:
Lobar consolidation
Patchy infiltrates
Pleural effusion
Microbiology
Selected severe cases:
Blood cultures
Viral PCR
Sputum studies (rarely possible in children)
Management
Supportive Care
Adequate fluids
Antipyretics
Oxygen if required
Antibiotic Therapy
If bacterial pneumonia is suspected.
Choice depends on:
Age
Severity
Local guidelines
Common first-line therapy:
Amoxicillin
Hospital Admission
Consider if:
Hypoxia
Significant respiratory distress
Poor feeding
Dehydration
Complications suspected
Intensive Care
May be required for:
Respiratory failure
Septic shock
Severe hypoxaemia
Complications
Respiratory
Pleural effusion
Empyema
Lung abscess
Pneumothorax
Systemic
Sepsis
Septic shock
Long-Term
Usually uncommon in previously healthy children.
Common Exam Traps
Trap 1
Tachypnoea is one of the most important clinical signs.
Trap 2
Crackles support the diagnosis but may be absent.
Trap 3
Not all children require a chest X-ray.
Trap 4
Hypoxia is an important severity marker.
Trap 5
Pleural effusion and empyema should be considered if recovery is poor.
Trap 6
Mycoplasma pneumonia is more common in school-aged children.
One Minute Revision
Pneumonia = infection of lung parenchyma.
Fever + cough + tachypnoea.
Tachypnoea is a key clinical sign.
Viral causes common in younger children.
Streptococcus pneumoniae is the commonest bacterial cause.
Amoxicillin is often first-line treatment.
Watch for pleural effusion and empyema.
Related Question of the Day
A 4-year-old child presents with fever, cough and tachypnoea. Which clinical sign is most helpful in supporting a diagnosis of pneumonia?
A. Strabismus
B. Tachypnoea
C. Rash
D. Tongue tie
E. Limp
Answer
B. Tachypnoea
Explanation
Tachypnoea is one of the most important clinical signs of pneumonia and is frequently tested in MRCPCH examinations.
Related Topics
Bronchiolitis
Asthma
Croup
Pleural Effusion
Empyema
Suggested References
NICE Guidance: Pneumonia in Children
BTS Guidelines for Community Acquired Pneumonia in Children
RCPCH Guidance
BNF for Children
Nelson Textbook of Pediatrics
Illustrated Textbook of Paediatrics
Kendig's Disorders of the Respiratory Tract in Children
Disclaimer
These notes are intended for MRCPCH revision and educational purposes only. They do not replace local, national or institutional guidelines. Clinical decisions should always be based on current guidance, senior advice and individual patient circumstances.
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