What is the most common cause of respiratory infections exacerbating asthma symptoms in pediatric patients and what is the best treatment approach?

Viral Respiratory Infections and Treatment in Pediatric Asthma

Viral respiratory infections are the most common cause of asthma exacerbations in pediatric patients, and inhaled corticosteroids are the preferred treatment for controlling asthma symptoms and preventing exacerbations. 1

Most Common Cause of Respiratory Infections Exacerbating Asthma

Viral Respiratory Infections

• Viral respiratory infections are the predominant trigger for asthma exacerbations in children under 5 years of age 1
• Among children 5 years and younger, viral respiratory infections are the most common cause of asthma-like symptoms 1
• These infections can lead to significant morbidity, with many children requiring emergency department visits or hospitalizations 1

Specific Pathogens

• Rhinovirus is the most frequently detected viral agent in children with asthma exacerbations 2
• Mycoplasma pneumoniae has also been identified as a significant pathogen in pediatric asthma exacerbations, with studies showing:
  • 20-42% prevalence in children with previously diagnosed asthma experiencing exacerbations 3, 4
  • Up to 45-50% prevalence in children experiencing their first asthma attack 5, 4
  • Higher rates of fever and abnormal breath sounds (rales) in infected children 5

Best Treatment Approach

Long-Term Control Medications

Inhaled Corticosteroids (ICS)

• Inhaled corticosteroids are the preferred treatment option for long-term control of persistent asthma in children 1
• They are recommended as first-line therapy for mild persistent asthma at low doses 1
• For moderate persistent asthma, either low-dose ICS with long-acting beta2-agonists OR medium-dose ICS is preferred 1

Treatment Algorithm Based on Severity:

1. Mild Persistent Asthma:

   • Preferred: Low-dose inhaled corticosteroids via nebulizer, MDI with holding chamber (with or without face mask), or DPI 1
   • Alternative options: Cromolyn (nebulizer preferred) or leukotriene receptor antagonist 1

2. Moderate Persistent Asthma:

   • Preferred: Low-dose inhaled corticosteroids with long-acting beta2-agonists OR medium-dose inhaled corticosteroids 1
   • Alternative: Low-dose inhaled corticosteroids with either leukotriene receptor antagonist or theophylline 1

3. For Recurring Severe Exacerbations:

   • Preferred: Medium-dose inhaled corticosteroids with long-acting beta2-agonists 1
   • Alternative: Medium-dose inhaled corticosteroids with either leukotriene receptor antagonist or theophylline 1

Acute Exacerbation Management

• For acute exacerbations, short-acting beta-agonists are the mainstay of immediate treatment 1
• When exacerbations are severe, systemic corticosteroids should be administered:
  • Adults: 30-60 mg prednisolone immediately, continuing each morning until two days after control is established 1
  • Children: 1-2 mg/kg body weight for one to five days; no tapering needed 1

Special Considerations for Infection-Triggered Exacerbations

• When M. pneumoniae infection is suspected or confirmed (fever, rales on examination), macrolide antibiotics should be added to standard asthma therapy 3
• Inhaled corticosteroids may have a protective effect against M. pneumoniae infections in asthmatic children 2

Criteria for Initiating Long-Term Control Therapy

Long-term control therapy should be strongly considered in children who:

• Have had more than three episodes of wheezing in the past year lasting more than 1 day and affecting sleep, AND have risk factors for persistent asthma 1
• Require symptomatic treatment more than twice weekly 1
• Experience severe exacerbations less than 6 weeks apart 1

Monitoring and Follow-up

• Regular assessment of asthma control is essential 1
• Monitor for:
  • Days off school due to asthma 1
  • Daytime and nighttime symptoms 1
  • Need for rescue medications 1
  • Activity limitations 1
• Height and weight should be documented regularly to monitor for potential growth effects of corticosteroids 1

Common Pitfalls and Caveats

• Asthma in early childhood is frequently underdiagnosed, receiving labels such as chronic bronchitis, wheezy bronchitis, or recurrent pneumonia 1
• Not all wheezing and coughing in children is due to asthma; consider other conditions like cystic fibrosis, foreign body aspiration, or congenital heart disease 1
• Hyposensitization (immunotherapy) is not indicated in the management of asthma 1
• Antibiotics have no place in the management of uncomplicated asthma but may be indicated when specific infections like M. pneumoniae are suspected 1, 3