Why are children with asthma, such as those with cough variant asthma and exercise-induced bronchospasm, more prone to frequent respiratory tract infections?

Why Children with Asthma Are More Prone to Respiratory Infections

The Bidirectional Relationship

Children with asthma experience more frequent respiratory infections because viral infections both trigger asthma exacerbations and are facilitated by the underlying airway inflammation and structural changes characteristic of asthma. 1

The relationship works in both directions:

• Viral infections are the predominant trigger for asthma exacerbations in children, with respiratory viruses detected in 80-85% of exacerbations in school-aged children 1
• Rhinovirus is the most common culprit, identified in approximately 35.6% of acute asthma exacerbations 2
• Airway inflammation in asthma creates vulnerability to viral infections through mechanisms including airway edema, mucus hypersecretion, and formation of inspissated mucus plugs that impair normal clearance mechanisms 1

Underlying Mechanisms

Airway Changes That Increase Infection Susceptibility

The structural and inflammatory changes in asthmatic airways create an environment more susceptible to viral infections:

• Airway hyperresponsiveness causes exaggerated bronchoconstrictor responses to viral stimuli 1
• Persistent airway remodeling includes sub-basement fibrosis, mucus hypersecretion, smooth muscle hypertrophy, and epithelial cell injury—all of which impair the airway's ability to clear pathogens 1
• Chronic inflammation may alter immune responses, making children more susceptible to viral infections 1

Viral Infections Amplify Asthma Pathology

Experimental evidence demonstrates that viral infections worsen asthmatic inflammation:

• Rhinovirus increases eosinophilic inflammation and airway hyperresponsiveness in allergic individuals 1
• Viral infections may require concomitant allergic processes to produce significant airway hyperresponsiveness, as shown in mouse models with RSV 1
• Different respiratory viruses vary in their "asthmagenic" potential, with some triggering more severe asthma responses than others 1

Your Child's Specific Situation

Frequency of Illness in Preschool-Aged Children

Yes, this frequency of illness is unfortunately normal for preschool-aged children with asthma. 3

• Preschool exposure dramatically increases viral infection frequency because young children in group settings experience 6-12 viral upper respiratory infections annually 1
• Children under 5 years with asthma are particularly vulnerable to viral respiratory infections as the predominant trigger for asthma-like symptoms 3
• The pattern you describe—initial improvement followed by worsening with fever—suggests either a secondary bacterial infection or a viral exacerbation of underlying asthma 4

The Cycle You're Experiencing

Your child's pattern reflects a common clinical scenario:

• Initial viral upper respiratory infection (the cough and runny nose) 2
• Partial recovery as the acute viral phase resolves 1
• Secondary worsening either from viral-triggered asthma exacerbation or new viral exposure at preschool 4
• Increased albuterol use at night indicates inadequate asthma control and suggests the need for controller therapy adjustment 3

Critical Management Considerations

When to Escalate Controller Therapy

Your child likely needs escalation of long-term controller therapy based on the increased rescue inhaler use. 3

The American Academy of Pediatrics recommends considering long-term control therapy intensification when:

• Rescue medication is needed more than twice weekly for symptom relief 3
• Nighttime symptoms require albuterol use, as you're experiencing 3
• Severe exacerbations occur less than 6 weeks apart 3

Immediate Action for Current Illness

For the current 48-hour episode with 102°F fever:

• Continue albuterol as needed for cough and respiratory symptoms 4
• Consider oral prednisolone 1-2 mg/kg/day for 3-5 days if your child has tachypnea, chest retractions, or moderate respiratory distress 4
• Contact your pediatrician to assess whether this represents a viral exacerbation requiring systemic corticosteroids 4

Common Pitfalls to Avoid

Diagnostic Confusion

Be cautious about the "cough variant asthma" diagnosis in very young children. 5

• Most children with isolated chronic cough do not have asthma, and airway inflammation studies show only 3 of 23 children with isolated chronic cough had asthma-type inflammation 1, 5
• However, your child has documented exercise-induced bronchospasm, which provides objective evidence of airway hyperresponsiveness and supports the asthma diagnosis 5
• The combination of exercise-induced symptoms plus response to albuterol distinguishes your child from those with isolated cough 5

Treatment Gaps

• Do not use over-the-counter cough and cold medications in young children due to lack of efficacy and potential toxicity 4
• Antibiotics have no role in uncomplicated viral-induced asthma exacerbations unless specific bacterial infection is suspected 3
• Inadequate use of preventive short-acting bronchodilators before exercise is common—only 23.1% of children use albuterol before exercise as recommended 6

Follow-Up Strategy

Schedule follow-up in 4-8 weeks to reassess asthma control and determine if controller therapy adjustment is needed 4. Document:

• Frequency of daytime symptoms 3
• Nighttime awakenings requiring albuterol 3
• Days missed from preschool 3
• Activity limitations 3
• Rescue inhaler use frequency 3

This assessment will guide whether to escalate from current montelukast therapy to inhaled corticosteroids or combination therapy 3.