New Research Highlights Specific Allergens that May Predispose Sensitized Children with Asthma to Upper Respiratory Infections

Indoor mouse and cockroach allergen exposure may predispose sensitized children with asthma to upper respiratory infections (URIs) and associated pulmonary outcomes, according to new research presented at the 2024 American Academy of Allergy, Asthma, and Immunology (AAAAI) annual meeting, February 23-26, 2024, in Washington, DC.

Among the 90 children (92% Black, 92% using public insurance) included in the study, however, cat and dog allergen concentrations were not associated with URI outcomes, according to presenting author Darlene Bhavnani, PhD, Dell Medical School, University of Texas at Austin, and colleagues.

“Emerging data suggests that Black children are more susceptible to [URI],” wrote investigators in the abstract. “Certain environmental allergen/irritant exposures are more common in disadvantaged communities of color and may contribute to differences in susceptibility to URI.”

To explore this further, Bhavnani and colleagues conducted the study to examine associations between indoor allergens and:

• URI,
• URI+cold symptoms (symptomatic URI),
• Symptomatic URI+reduced lung function (percent predicted FEV1<80%),
• Symptomatic URI+pulmonary eosinophilic inflammation (fractional exhaled nitric oxide [FeNO] level ≥35 ppb)

Researchers used longitudinal data collected from sensitized children enrolled in the Environmental Control as Add-on Therapy for Childhood Asthma (ECATCh) clinical trial (NCT02251379). The ECATCh study (evaluated the effects of adding on an environmental home intervention to standard asthma medication management among children and adolescents with asthma.

For the current study, Bhavnani and coauthors measured allergen concentrations in home air samples (mouse) and in settled dust (cockroach, cat, and dog). They tested nasal mucus for rhinovirus, respiratory syncytial virus, influenza, coronavirus, adenovirus, parainfluenza, and human metapneumovirus, according to the abstract.

Investigators used odds ratios (ORs) adjusted for age, sex, month of study, season, health insurance, and household size to evaluate associations between a doubling in allergen concentrations and URI outcomes.

Investigators reported 118 observations among the study’s 90 participants of which 32 (27%) were positive for URI.

Researchers found that mouse allergen concentration was associated with symptomatic URI (URI+cold symptoms; OR 1.24, 95% CI 0.90-1.72), URI+reduced lung function (OR 1.58, 95% CI 1.10-2.27), and URI+pulmonary eosinophilic inflammation (OR 1.42, 95% CI 0.98-2.04).

They found that cockroach allergen concentration was associated with symptomatic URI (OR 1.30, 95% CI 0.98-1.71) and URI+reduced lung function (OR 1.79, 95% CI 1.05-3.03) but not associated with URI+pulmonary eosinophilic inflammation.

Cat and dog allergen concentrations were not associated with any URI symptoms, added researchers.

Source: Bhavnani D, Beaudenon-Huibregtse S, Davis M, et al. Indoor allergen exposure and its influence on upper respiratory infections and pulmonary outcomes among children with asthma. J Allergy Clin Immunol. 2024;153:AB367. doi:10.1016/j.jaci.2023.11.875