Pediatric respiratory medicine

A potential paradigm shift in the management of mild asthma occurred in 2019 with new recommendations from Global Initiative for Asthma (GINA): “For safety, GINA no longer recommends treatment of asthma and adolescents with short acting beta agonist (SABA) alone. ” For very mild asthmatics (symptoms <2/month, no risk factors for exacerbations) GINA recommends low-dose inhaled corticosteroid (ICS) with formoterol as needed as the preferred option and as an alternative to taking an ICS inhaler with every administration of SABA. For individuals with symptoms 2 or more times a month or risk factors for exacerbation, GINA continues to recommend the use of regular low dose ICS with SABA as needed. However, especially if there is concern for adherence, ICS-formoterol as needed is provided as a first line option as well. The primary stated goal of these recommendations is the avoidance of exacerbations. The Canadian Thoracic Society (CTS) asthma guideline panel is currently undertaking systematic reviews and will be updating the CTS asthma guidelines when this is complete. In the meantime, the GINA recommendations provide clinicians additional options to manage patients with mild asthma. Further insight was gained into potential differential responses to therapy based on ethnicity in a study of different step-up regimens for Black Americans who were not well controlled on fluticasone 100mcg daily. In the pediatric arm (6–11 years of age) children received 14weeks each of twice daily fluticasone 100mcg, fluticasone 250mcg, fluticasone 100mcg/salmeterol 50mcg and fluticasone 250mcg/salmeterol 50mcg. In the adult and adolescent arm, consistent with current guidelines, the addition of a long acting beta agonist was more likely to have a beneficial response than increasing the dose of inhaled corticosteroids; in 6–11 year olds, there was an equal likelihood to responding to increased inhaled corticosteroids or adding a long acting beta agonist, and there was a further likelihood of an increase in high dose inhaled corticosteroids. This raises an important issue for future research regarding the need to ensure the representation of diverse populations in asthma studies. Clinically, the results of this study are consistent with our current CTS recommendations for 6 to 11-year-old patients to increase to medium dose ICS prior to the start of long acting beta agonists. Although there may be further benefit in black children to consider increasing to a high dose inhaled corticosteroid from an efficacy point of view, concerns about ICS side effects limit this without further large studies that are better designed to look at the safety of this approach over a longer period. Two publications from Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC2000) birth cohort support the idea that the presence of fixed airway disease and airway hyperactivity is already present in the neonatal period and may be the cause of the asthma exacerbations rather than a consequence of them. This cohort followed 411 Danish infants born to mothers with a history of asthma and involved regular clinical assessments included spirometry, plethysmography and methacholine challenge testing in the neonatal period and at regular intervals until age 13. Diagnosis and treatment during the follow up was based preestablished protocols. Children who were diagnosed with asthma at any point during or before age 13 already had reduced FEV0.5 and increased bronchial hyper-reactivity on methacholine challenge testing at 1month of age. Furthermore, this impairment continued throughout the follow up period even if symptoms resolved. There was also no difference between children who had persistent asthma to 13 years of age and those in whom the diagnosis was transient. Children with asthma who had at least one exacerbation had increased airway resistance (sRAW) compared to those with asthma and no exacerbations and the more exacerbations they had the higher the resistance was. In the small subset of children (n1⁄4 13) who had sRAW measurements both before and after an exacerbation, there was no further worsening, which suggested that increased airway resistance was predisposed to exacerbations rather than developed as a consequence. This is consistent with current evidence. No publications to date have shown meaningful long-term disease modifying impact from regular inhaled corticosteroids in children. This supports our primary goals of therapy in children, which should be asthma control and exacerbation avoidance, rather than attempts to modify the disease process.