Nearly Eight Million Spaniards to Suffer from Pollen Allergy This Year, According to SEAIC

In Spain, the arrival of spring 2026 has brought with it a familiar yet increasingly burdensome reality for nearly eight million people: seasonal allergic rhinitis triggered by airborne pollen. According to the Spanish Society of Allergology and Clinical Immunology (SEAIC), this figure represents approximately 17% of the national population, marking a steady rise over the past decade linked to climate change, urban pollution, and prolonged pollen seasons. What was once a seasonal nuisance is now recognized as a significant public health concern, with implications for productivity, sleep quality, and comorbid asthma development.

Key Clinical Takeaways:

• Nearly 8 million Spaniards suffer from pollen allergy this spring, with grass and olive tree pollens being the primary triggers.
• Allergic rhinitis significantly increases the risk of developing asthma, particularly in children and young adults.
• Effective management includes allergen avoidance, pharmacotherapy, and allergen immunotherapy, with referral to specialists recommended for moderate-to-severe cases.

The pathogenesis of seasonal allergic rhinitis involves an IgE-mediated hypersensitivity reaction wherein pollen antigens trigger mast cell degranulation in the nasal mucosa, releasing histamine, leukotrienes, and cytokines that cause the characteristic symptoms of sneezing, nasal congestion, rhinorrhea, and ocular irritation. In genetically predisposed individuals, repeated exposure leads to Th2 immune polarization and epithelial barrier disruption, contributing to chronic inflammation. Recent longitudinal data from the ECRHS III study, published in The Lancet Respiratory Medicine in 2025, followed over 12,000 European adults and found that individuals with persistent allergic rhinitis had a 2.8-fold increased risk (95% CI: 2.1–3.7) of developing adult-onset asthma within five years, underscoring the importance of early intervention.

“We are seeing a clear progression from allergic rhinitis to asthma in a significant subset of patients, especially when symptoms are poorly controlled. This is not just about quality of life—it’s about preventing long-term respiratory morbidity.”

Current standard of care emphasizes a stepwise approach: intranasal corticosteroids remain first-line pharmacotherapy for moderate-to-severe symptoms, supported by robust evidence from double-blind placebo-controlled trials. Antihistamines, particularly second-generation agents, are effective for mild intermittent cases. However, for patients with inadequate response or those seeking disease modification, allergen immunotherapy (AIT)—administered either subcutaneously (SCIT) or sublingually (SLIT)—represents the only treatment capable of altering the natural history of the disease. A 2024 meta-analysis in JAMA Allergy and Clinical Immunology, which pooled data from 67 RCTs involving over 9,000 participants, confirmed that both SCIT and SLIT significantly reduce symptom scores and medication apply, with SLIT demonstrating a favorable safety profile, including very low rates of systemic reactions (<0.1%).

Funding for much of this research has come from public health initiatives, including the EU Horizon Europe program and Spain’s Carlos III Health Institute, ensuring transparency and minimizing industry bias. Notably, the SLIT tablet for grass pollen allergy (Grastek®) was developed through a collaboration between ALK-Abelló and Merck, with pivotal Phase III trials conducted across multiple European centers, including Barcelona and Seville, under EMA oversight.

Despite advances in treatment, gaps in care persist. Underdiagnosis remains common, particularly among adolescents and elderly populations who may attribute symptoms to recurrent colds. Adherence to daily nasal corticosteroid regimens is often suboptimal due to misconceptions about steroid safety. Addressing these barriers requires not only patient education but also improved access to specialty care.

For individuals experiencing persistent nasal congestion, sleep disruption, or asthma-like symptoms during pollen season, timely evaluation by a specialist is crucial. It is strongly advised to consult with vetted board-certified allergists who can perform skin prick testing or specific IgE assays to identify causative allergens and tailor treatment plans. Those requiring long-term management may benefit from consultation with pulmonologists to assess for comorbid asthma, while patients considering immunotherapy should seek centers experienced in administering SLIT protocols under medical supervision.

As climate models predict longer and more intense pollen seasons across the Iberian Peninsula, the burden of allergic disease is likely to grow. Proactive public health strategies—including urban planning that considers low-allergen landscaping and enhanced pollen monitoring networks—will be essential. Meanwhile, clinicians must remain vigilant in recognizing allergic rhinitis not as a trivial condition, but as a modifiable risk factor for more serious respiratory disease.

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.