Pathophysiology
Clinical meaning
The foundation of asthma management separates controller therapy (daily anti-inflammatory agents) from reliever therapy (rescue bronchodilators). ICS is the cornerstone controller reducing airway inflammation, hyperresponsiveness, and remodeling. GINA 2024 introduced a paradigm shift: anti-inflammatory reliever (AIR) therapy with low-dose ICS-formoterol PRN replaces SABA-only rescue across all steps. This ensures every reliever dose delivers anti-inflammatory therapy, reducing the dissociation between symptom relief and inflammation control. The as-needed ICS-formoterol approach reduces severe exacerbations by 60% compared to SABA-only reliever. For patients on traditional fixed-dose ICS, SABA remains the reliever, but SABA overuse (> 3 canisters/year) is a marker of poor control and increased mortality risk. The clinician must understand these distinctions to prescribe appropriately.