Among patients with asthma, viral infection and allergic sensitization have both been identified as major risk factors for exacerbations. Evidence has also linked allergic sensitization with impaired anti-viral immune response, suggesting patients with allergic asthma may be at increased risk for bacterial respiratory infection. However, little is known regarding the effect of interventions targeting allergy in this patient population.

For a study published in Annals of Allergy, Asthma & Immunology, Christian Woehlk, BSc. med., and colleagues sought to determine whether patients with allergic asthma are more likely to be prescribed antibiotics targeting respiratory infections when compared with those with non-allergic asthma. “We also speculated that hyposensitization with allergen-specific immunotherapy would reduce the risk of respiratory infections requiring antibiotics in patients with allergic asthma,” adds Woehlk.

The researchers found that allergic asthma was associated with an increased risk of filling at least two antibiotic prescriptions per year when compared with non-allergic asthma (odds ratio [OR], 1.28). “Interestingly, among patients with allergic asthma, allergen-specific immunotherapy appeared to have a protective effect on the risk of filling antibiotic prescriptions (OR, 0.76.),” says Woehlk. “These findings support existing evidence on the potential mechanism between allergic sensitisation and impaired immune response, as well as allergic sensitization in asthma being a potentially modifiable risk factor for respiratory infections.”

Woehlk hopes the study will contribute to the understanding of the clinical impact of allergy in asthma, as a potential modifiable risk factor for respiratory infections and associated exacerbations. “Our study supports the relevance of future studies investigating the immunologic mechanisms linking allergic sensitization and impaired immune response in patients with allergic asthma,” he notes.