After an allergen challenge, the allergic inflammatory response disappears spontaneously. The initiation of the resolution of the inflammatory response is now recognized as a dynamic process, involving active biochemical programs that enable inflamed tissues to return to homeostasis. Recent data established key roles of different specific lipid mediators in the endogenous counter-regulation of inflammation and activation of resolution. Only little is known about kinetics of these specialized pro-resolving lipid mediators during acute allergic inflammation. Therefore, the primary propose of our study is to characterize the temporal evolution of cellular inflammation and specific lipid mediators after allergen challenge.

Eligibility criteria:

Inclusion Criteria

• Allergic rhinitis during the grass pollen season with or without asthma, with at least one of the following symptoms: nasal congestion, itching, rhinorrhea, sneezing
• Grass pollen sensitization determined by a positive skin prick test and / or presence of specific IgEs to a grass pollen allergen extract

Exclusion Criteria:

• Smoker
• Specific immunotherapy with grass allergens or other respiratory allergen for inclusion.
• Current exhibition to another clinically relevant respiratory allergen