The forgotten billion: bridging the global allergy care chasm through scalable, equity-driven strategies

Background Allergic diseases affect more than one billion people globally, yet care access is profoundly unequal. The “forgotten billion” refers to underserved populations—especially in LMICs and marginalized groups within high-income countries—who face disproportionate morbidity and preventable deaths due to gaps in diagnosis, essential medicines, immunotherapy and biologics, trained workforce, and policy prioritization. Objective To synthesize recent (2014–2026) evidence on global burden and inequities in allergic disease care, analyze system-level gaps, review scalable innovations, present diverse case studies, and propose prioritized recommendations, monitoring frameworks, and a research and financing agenda. Methods We conducted a structured narrative review of peer-reviewed literature and global guidance documents, focusing on burden metrics (prevalence, DALYs, mortality), access indicators, interventions (task-sharing, telemedicine, point-of-care tools, immunotherapy access, digital health, procurement/policy levers), and implementation science frameworks. Sources prioritized include WHO materials and guideline bodies (GINA, ARIA, EAACI), plus global reports and primary studies. Results Asthma illustrates the equity chasm: in 2019 it caused approximately 21.6 million DALYs and approximately 461,000 deaths globally, with approximately 90% of burden borne in LMICs and most deaths occurring in LMICs. Systematic reviews show essential inhaled asthma medicines—especially inhaled corticosteroids (ICS) and ICS-containing combinations—are often unavailable or unaffordable in LMICs. Scalable strategies with documented impact include task-shifted care packages (Malawi), standardized primary care training (South Africa), community health worker home visiting (Boston), and public-sector access programs (Brazil), alongside national allergy strategies (Finland). Conclusions Closing the allergy care chasm requires shifting from specialist-centric innovation to systems-first equity: universal access to essential medicines and equitable pathways to targeted therapies for severe disease, standardized primary care delivery with task-sharing, market-shaping and pricing policy reform, digitally enabled self-management designed to reduce (not widen) inequities, and integrated environmental action. Implementation must be measured with equity-sensitive frameworks and supported by durable financing aligned with UHC and NCD agendas.