Background Cockroach and mouse allergens have both been implicated as causes in inner-city asthma morbidity in multicenter studies, but whether both allergens are clinically relevant within specific inner-city communities is unclear. Objective: Our study aimed to identify relevant allergens in Baltimore City. Methods One hundred forty-four children (5–17 years old) with asthma underwent skin prick tests at baseline and had clinical data collected at baseline and 3, 6, 9, and 12 months. Home settled dust samples were collected at the same time points for quantification of indoor allergens. Participants were grouped based on their sensitization and exposure status to each allergen. All analyses were adjusted for age, sex, and serum total IgE level. Results Forty-one percent were mouse sensitized/exposed, and 41% were cockroach sensitized/exposed based on bedroom floor exposure data. Mouse sensitization/exposure was associated with acute care visits, decreased FEV1/forced vital capacity percentage values, fraction of exhaled nitric oxide levels, and bronchodilator reversibility. Cockroach sensitization/exposure was only associated with acute care visits and bronchodilator reversibility when exposure was defined by using bedroom floor allergen levels. Mouse-specific IgE levels were associated with poor asthma health across a range of outcomes, whereas cockroach-specific IgE levels were not. The relationships between asthma outcomes and mouse allergen were independent of cockroach allergen. Although sensitization/exposure to both mouse and cockroach was generally associated with worse asthma, mouse sensitization/exposure was the primary contributor to these relationships. Conclusions In a community with high levels of both mouse and cockroach allergens, mouse allergen appears to be more strongly and consistently associated with poor asthma outcomes than cockroach allergen. Community-level asthma interventions in Baltimore should prioritize reducing mouse allergen exposure.

Studies have provided significant evidence of the association between many indoor pollutants and allergens and asthma morbidity, and have also demonstrated the efficacy of multifaceted indoor environmental interventions in childhood asthma. There is also a growing body of evidence suggesting that some indoor pollutants and allergens may increase the risk of developing asthma. Future studies should examine mechanisms whereby environmental exposures may influence asthma pathogenesis and expand the current knowledge of susceptibility factors for indoor exposures.

Over the last 2 to 3 decades, significant advances have been made in understanding the role that indoor allergen exposures play with regard to respiratory health. Multiple studies have confirmed that sensitization and exposure to indoor allergens can be a risk factor for asthma morbidity. Environmental interventions targeting key indoor allergens have been evaluated with the aims of examining their causal effects on asthma-related outcomes and identifying clinically efficacious interventions to incorporate into treatment recommendations. Historically, it appeared that the most successful intervention, as performed in the Inner-City Asthma Study, was individually tailored, targeting multiple allergens in a predominantly low-income, minority, and urban pediatric population. Recent studies suggest that single-allergen interventions may be efficacious when targeting the most clinically relevant allergen for a population. In this article, we review recent literature on home environmental interventions and their effects on specific indoor allergen levels and asthma-related outcomes.