Recurrent Obstructive Bronchitis: When the Cough Won't Stop

More than just a "harmless childhood cough"

More than just a "harmless childhood cough"

Lukas, 2 years old, has been coughing for weeks. His breathing is wheezing, he eats poorly and seems tired. The pediatrician diagnoses recurrent obstructive bronchitis - for the third time this year. Like Lukas, about 30% of all children suffer from this condition at least once before their third birthday 4 . But what lies behind this complex term? And why can a seemingly simple cough threaten lung function in the long term?

Key Facts
  • Affects 30% of children under 3
  • Recurrent episodes of airway obstruction
  • Often triggered by viral infections

What happens in the bronchi?

Recurrent obstructive bronchitis is characterized by repeated episodes of airway narrowing (obstruction) and inflammatory mucosal swelling. Triggers are usually viruses (e.g. RSV, rhinoviruses) that initiate a cascade of inflammatory processes:

Mucus Flooding

Enlarged goblet cells produce excessive viscous mucus.

Inflammatory Storm

Neutrophils release elastase - an enzyme that activates EGFR receptors of bronchial cells and further stimulates mucus production 1 .

Muscle Spasms

The bronchial muscles cramp, narrowing the airways.

Risk Factors Overview

Factor Mechanism
Premature birth Immature lungs with reduced defense capacity
Secondhand smoke Destroys cilia, reduces mucus transport
Air pollutants (PM, NO₂) Chronic irritation of bronchial mucosa
Atopic predisposition Genetically determined airway hypersensitivity

Key Experiment: Neutrophil Traps and Their Fatal Role

A groundbreaking study in horse models (2025) investigated the relationship between neutrophil extracellular traps (NETs) and chronic bronchial obstruction . NETs are net-like DNA structures that neutrophils release to defend against pathogens - but when overactive, they damage their own tissue.

Methodology:

  1. Sample collection: Bronchoalveolar lavage (BAL) in 64 horses with severe bronchial obstruction vs. healthy control group.
  2. NETs detection: Staining of Citrullinated Histone H3 (Cit-H3), a NETs marker.
  3. Functional tests:
    • Measurement of DNase activity (degrading enzyme)
    • Analysis of anti-neutrophil antibodies (ANCAs)
  4. Blood neutrophil isolation: Stimulation with PMA to induce NETs.
Results (Excerpt)
Parameter Sick Group Healthy Group p-value
Cit-H3-positive cells (%) 42.1 ± 5.3 6.7 ± 1.2 <0.001
DNase activity (U/ml) 12.4 ± 3.1 32.8 ± 4.7 <0.001
eCATH (ng/ml) 185.9 ± 28.3 62.4 ± 10.1 <0.001
Conclusion
  • Sick animals showed more NETs, less degrading DNase and higher levels of the pro-inflammatory peptide equine Cathelicidin (eCATH).
  • Blood neutrophils formed more NETs even without stimulus - evidence of systemic inflammation.
  • Clinical relevance: NETs clog airways, damage bronchial epithelium and trigger autoimmune reactions (ANCAs).

Long-term Consequences: From Bronchitis to COPD?

A recent study with over 800,000 patients (2025) shows alarming data: 75.9% of COPD patients had previously experienced chronic bronchitis symptoms 5 . Particularly critical:

"Lung Killer" Triad

Repeated inflammations lead to:

  1. Thickening of bronchial walls (Reid-Index >0.4) 1
  2. Loss of lung elasticity
  3. Irreversible airflow obstruction
Systemic Effects

Chronic inflammation promotes comorbidities:

  • Cardiovascular risk: 51.9% of COPD patients suffer from hypertension or heart failure 7 .
  • Metabolic disorders: Insulin resistance due to TNF-α and IL-6.

Prevention and Therapy: Protecting Young Lungs

Acute Therapy During an Attack
  • Bronchodilators: Salbutamol inhalation for muscle relaxation.
  • Antibiotics: Only for bacterial superinfection (e.g. H. influenzae).
  • Physiotherapy: Breathing techniques for secretion mobilization.
Long-term Strategies
  1. Parental smoking cessation: Reduces attack frequency by 30% 1 .
  2. Vaccinations: Against influenza, RSV and pneumococci.
  3. Environmental control:
    • Particulate filters indoors
    • No pets for sensitized children
  4. Recurrence prevention: For >3 episodes/year:
    • Inhaled corticosteroids (low dose)
    • Montelukast (leukotriene inhibitor) 4
When to Consider Asthma?
Warning Signs:
  • Obstructions also outside infections
  • Nocturnal cough with dyspnea
  • Positive family history for allergies
Diagnostics:
  • Therapeutic trial with 2-3 months ICS/LTRA
  • FeNO measurement (nitric oxide in exhaled air) 4

Conclusion: Act Early - Breathe for Life

Recurrent obstructive bronchitis is not a "banal childhood cough". Modern research shows: repeated inflammations leave microstructural scars in the bronchi - even when symptoms subside. The good news: early intervention can often break the vicious cycle of inflammation and tissue remodeling. Parents should therefore:

  • Minimize risk factors (especially tobacco smoke!)
  • Keep an attack diary
  • Seek pneumological consultation for repeated obstructions

Because every episode that is prevented is a gain for lung health into adulthood.

Scientific Reagent Check

Citrullinated Histone H3 (Cit-H3)

NETs detection in tissue samples

FeNO Meter

Quantifies nitric oxide as inflammation marker

DNase Assay

Measures enzyme activity for NETs degradation

eCATH-ELISA

Detects inflammatory peptides in BALF

References