We all know that healthy children love to collect illnesses like baseball cards (for you younger providers… people used to collect baseball cards for fun). Just as they are recovering from one illness, they catch another. This is why a family may perceive their child to “always be sick.” While we may need to ponder Kawasaki Disease or oncologic conditions as a cause of reported prolonged illness, we also know that it often is more likely two successive viral infections. There are times, however, when having a recurrent problem should raise your concern. We’ve discussed Recurrent Croup and Recurrent Abdominal Pain previously. Now let us ponder another recurrent diagnosis that may be the clue to important underlying pathology – Recurrent Pneumonia:

Recurrent Pneumonia in Pediatrics: Basics

• Pneumonia is an acute inflammation of the lower respiratory tract. [Chen, 2021]
  • It is one of the leading causes of morbidity and mortality in children worldwide.
  • ~6% of infants experience at least one episode of pneumonia during the first 2 years of life [Montella, 2017]
  • Some children will experience more than episode of pneumonia during childhood, but not necessarily met definition of “recurrent pnuemonia.”

• Recurrent Pneumonia is defined as: [Montella, 2017]
  • At least 2 episodes of pneumonia in 1 year OR 3 episodes ever
  • With interval radiographic clearing

• Recurrent Pneumonia occurs in ~7-9% of children with Community Acquired Pneumonia (CAP).

• Recurrent Pneumonia can be due to: [Montella, 2017]
  • Minor, self-limiting problems and unfortunate luck
  • Underlying disease that may lead to significant morbidity or mortality.

Recurrent Pneumonia in Pediatrics: Red Flags?

Since Recurrent Pneumonia may be relatively benign or may be a clue to an important underlying pathology, it is challenging to know how to evaluate it. Montella, et al. discussed some important aspects to consider when trying to take a reasonable approach: [Montella, 2017]

• Risk Factors that are associated with developing Recurrent Pneumonia: [Montella, 2017]
  • Prematurity / Bronchopulmonary Dysplasia
  • Atopy / Defective Innate Immune System
  • Tobacco Smoke Exposure
  • Social Over-crowding
  • Exposure to air pollutants

• Characteristics that are associated with LOWER risk of having underlying pathology: [Montella, 2017]
  • Pneumonia WITHOUT other organ or system involvement
  • Long period of clinical wellness between pneumonia episodes
  • Normal growth and examination
  • No concerning family history of genetic or infectious disorders
  • Quick response to treatment
  • Complete recover after treatment

• Characteristics that are associated with HIGHER risk of having underlying pathology: [Montella, 2017]
  • Unexplained death in the family
  • Unusual organism
  • Extrapulmonary infection
  • Otitis Media or sinusitis in 1st month of life
  • Sudden onset of pneumonia symptoms
  • Chronic sputum production / moist cough
  • Severe symptoms after feeds or when lying down
  • Continuous, unremitting, or worsening symptoms
  • Failure of treatment
  • Digital Clubbing
  • Weight loss, Failure to Thrive
  • Chest deformity
  • Signs of cardiac disease
  • Persistent crackles on exam for 8 weeks or more

Recurrent Pneumonia in Pediatrics: Pathology to Consider

For Recurrent Pneumonia occurring in same lobe: [Montella, 2017]

• Right Middle Lobe Syndrome
• Localized Airway Obstruction
  • Bronchial Foreign Body
  • Tumor
  • Congenital webs or rings
• Localized Airway Compression
  • Vascular ring or Pulmonary artery sling
  • Cardiomegaly
  • Mediastinal tumor
• Parenchymal Disease
  • Congenital malformation
  • Lung cancer

For Recurrent Pneumonia occurring in different/multiple lobes: [Montella, 2017]

• Systemic Immune Disorders
• Genetic Disease
• Neuromuscular Disorders
• Autoimmune Disease
• Granulomatous Disease
• Pulmonary Hemorrhagic Disorders
• Drug Toxicity
• Airway Anomalies
• Airway Obstruction
• Recurrent Aspiration

Evaluation: [Montella, 2017]

Initial evaluation can often be based on whether the Recurrent Pneumonia has been involving the same lobes or not.

• Same Region:
  • Fiberotic Bronchoscopy is often first choice
  • Chest CT may also be beneficial

• Different Lobes:
  • Since the Ddx list includes a wide variety of systemic conditions, it is best to tailor initial work up based on individual’s history and exam.
  • Immune evaluation, Sweat Chloride testing, TB Testing, 24 hour pH probes, Echocardiogram, etc. may all be necessary.
  • Chest CT and bronchoscopy may be warranted still, but may be performed as second line.

Moral of the Morsel

• Some times you are just unlucky. Not all Recurrent Pneumonias are due to ominous pathology.
• Look and ask for other clues. History is important in determining who is at greater risk for underlying pathology.
• Same side or Different? The Recurrent Pneumonia DDx list is long, but you can help the process of sorting it out by considering whether the pneumonia is always involving the same area.

References