The most common trigger for acute asthma episode in the very young child is:

The most common trigger for acute asthma episode in the very young child is:

• A. Outdoor allergens
• B. Exercise
• C. Tobacco smoke
• D. Respiratory infections

Answer: (D)

Viral respiratory infections are the most common trigger for acute asthma episodes in very young children. When a viral illness hits, the airways become inflamed, swollen, and filled with mucus. In infants and toddlers, the airways are already narrow, so this inflammation quickly leads to bronchoconstriction and wheezing, producing an acute asthma flare with cough, shortness of breath, and chest tightness. While outdoor allergens, exercise, and tobacco smoke can worsen asthma, they are less likely to precipitate an acute attack in this age group. Exercise-induced wheeze tends to appear in older kids with regular exertion, and outdoor allergen–triggered symptoms are more common in children with known atopy. Tobacco smoke is a major aggravating factor and risk general, but the immediate trigger for most young children’s acute episodes remains a viral infection.

Viral respiratory infections are the most common trigger for acute asthma episodes in very young children. When a viral illness hits, the airways become inflamed, swollen, and filled with mucus. In infants and toddlers, the airways are already narrow, so this inflammation quickly leads to bronchoconstriction and wheezing, producing an acute asthma flare with cough, shortness of breath, and chest tightness.

While outdoor allergens, exercise, and tobacco smoke can worsen asthma, they are less likely to precipitate an acute attack in this age group. Exercise-induced wheeze tends to appear in older kids with regular exertion, and outdoor allergen–triggered symptoms are more common in children with known atopy. Tobacco smoke is a major aggravating factor and risk general, but the immediate trigger for most young children’s acute episodes remains a viral infection.