Asthma-Like Symptoms, Risk Factors Identified Among Young Children

Asthma-like symptoms are common among young children, yet the underlying factors that contribute to this burden of disease have remained unclear. A recent study has found unique, age-specific risk factors for asthma-like symptoms in the first 3 years of life.

“This study identifies several risk factors for the burden of asthma-like symptoms during early childhood using prospective daily diary recordings of symptoms from birth until age 3 years,” wrote the researchers. “We furthermore describe their unique age-related symptom patterns.”

The results of this population-based cohort study were published in The Journal of Allergy and Clinical Immunology: In Practice.

The study included 700 children from a mother and child cohort, followed respectively from birth. Asthma-like symptoms were recorded in daily diary entries up until the age of 3 years. Asthma-like symptoms were defined by the cohort as cough, wheeze, and/or shortness of breath severely affecting the well-being of a child.

The primary outcome of this study was the prevalence of episodes for asthma-like symptoms, defined as asthma-like symptoms lasting more than 3 consecutive days. The secondary outcome was to identify risk factors and be able to predict the duration of these episodes.

Possible risk factors were identified using prior studies on known risk factors for childhood asthma, respiratory tract infections, and respiratory symptoms/asthma-like symptoms. Additional factors considered included the child’s sex, birth weight, and atopic predisposition and prenatal, perinatal, and postnatal exposures.

In total, 556 (79%) children had more than 90% diary entry completeness and were included in the researchers' analysis.

The children had a median (IQR) of 5 (2-11) episodes with asthma-like symptoms in the first 3 years of life, with 1 episode (0-3) in the first year, 2 (1-5) in the second year, and 1 (0-3) in the third year. Additionally, the asthma-like symptoms lasted a median 5 (3-10) days.

The analysis identified 9 possible risk factors for asthma-like symptoms among children in the first 3 years of life:

• Male sex: 22% more episodes
• Birth weight per 2.2-lb decrease: 19% more episodes
• Gestational age per 1-week decrease: 5% more episodes
• Pediatric atopic dermatitis: 19% more episodes
• Maternal asthma: 49% more episodes
• Maternal use of antibiotics during pregnancy: 20% more episodes
• Maternal use of antibiotics in the first year of life: 22% more episodes
• Asthma exacerbation polygenic risk score per SD increase: 22% more episodes
• Airway immune score per SD increase: 9% more episodes

Additionally, maternal asthma, preterm birth, caesarian section, and low birth weight were associated with increasing impact with age, up until 10 years. In contrast, having siblings at the time of birth was associated with decreased impact with age.

Lastly, every additional risk factor increased episodes by 34% (incidence rate ratio, 1.34; 95% CI, 1.21-1.46; P < .001).

“Using unique day-to-day diary recordings, we identified risk factors for the burden of asthma-like symptoms in the first 3 years of life and describe their unique age-related patterns,” concluded the researchers. “This provides novel insight into the origin of asthma-like symptoms in early childhood, which potentially pave a path for personalized prognostics and treatment.”

Reference

Kyvsgaard JN, Krogsgaard Chawes BL, George Horner DL, et al. Risk factors and age-related patterns of asthma-like symptoms in early childhood. The Journal of Allergy and Clinical Immunology: In Practice. Published online March 6, 2023. doi:10.1016/j.jaip.2023.02.031