Pediatric asthma patients should be considered priority for flu vaccine

A separate study cited by Dr. Merckx and her associates observed the same outcome for rhinovirus patients but more patients diagnosed with nonrhinovirus pathogens, especially human metapneumovirus (hMPV) and PIV, had moderate, rather than severe, symptoms and were much more likely to experience higher treatment failure, particularly those infected with RSV, influenza, and PIV.

“It appears reasonable to pursue strategies to improve immunization coverage for influenza and invest in efforts for the development of vaccines for RSV and rhinovirus,” they said.

In cases in which respiratory pathogens were present (especially nonrhinovirus pathogens), greater treatment failure occurred, despite use of inhaler and corticosteroids. The researchers noted that severity of condition at time of treatment and patient response to treatment should be considered as two separate, distinct dimensions of viral infection impact in children with acute asthma. “The high prevalence of rhinovirus C in children presenting with asthma exacerbation, its presumed association with asthma-related hospitalization, and its peak in the fall,” also should be considered as a leading cause for more potential severe disease.

Dr. Merckx and her associates did point to several possibly significant implications with their findings. Intensifying treatment using inhaled anticholinergics or magnesium sulfate could block the vagally mediated reflex bronchoconstriction typically seen in cases of asthma exacerbation worsened by viral infection. Although these therapies currently only are used only in severe reactions, it may be useful to examine their efficacy in any cases triggered by RSV, influenza, and PIV because these have been associated with a poor treatment response.

While it still is necessary to clarify its mechanism of action, azithromycin’s demonstrated benefit in preschoolers with severe reactions suggests it could be a possible alternative pathogen–nonspecific therapy to address antineutrophilic inflammation, they said.

Any treatment intensification would first require clear identification of responsible pathogens using on-site diagnostic measures in the ED. Until such testing is possible, preventive measures need to be prioritized, they advised.

Dr. Merckx had no relevant disclosures; two of her associates reported receiving grants, salary rewards, and/or unrestricted donations from various pharmaceutical companies or foundations.

SOURCE: Merckx J et al. Pediatrics. 2018 Jun;142(1):e20174105.