Seasonal Local Allergic Rhinitis in Areas With High Concentrations of Grass Pollen

Area of Science:

• Allergology and Immunology
• Otorhinolaryngology

Background:

• Local allergic rhinitis (LAR) is a distinct phenotype of allergic rhinitis.
• It is characterized by localized nasal mucosal immune responses.
• LAR occurs in patients with negative skin prick tests (SPT) and undetectable serum specific IgE (sIgE).

Purpose of the Study:

• To investigate the prevalence and characteristics of LAR.
• Focus on geographic areas with high grass pollen exposure.
• Evaluate clinical and immunological aspects of LAR in this context.

Main Methods:

• Cross-sectional observational study in central Spain.
• Included 61 patients with seasonal rhinitis and negative SPT/sIgE.
• Utilized clinical questionnaires, serum IgE, and nasal allergen provocation tests (NAPT) with Phleum species.

Main Results:

• Seasonal LAR was identified in 37 patients (61%).
• Adolescents and children comprised 11% of LAR cases, with 14% onset in childhood.
• Persistent-moderate nasal symptoms and conjunctivitis (95%) were common; 41% reported disease worsening.

Conclusions:

• Grass pollen-induced LAR is significant in patients with allergic rhinitis symptoms but negative SPT.
• This occurs in regions with high allergenic pollen loads.
• LAR should be considered in the differential diagnosis of rhinitis.