We have demonstrated the detection of proallergic cytokines in the nasal secretions after antigen challenges. Our aim was to determine the secretion kinetics of chemokines (interleukin [IL]-8, macrophage inflammatory protein-1 alpha [MIP-1 alpha], and RANTES) and other cytokines (IL-1 beta and granulocyte/macrophage colony-stimulating factor [GM-CSF] after allergen challenges and their inhibition by steroid therapy. Ten allergic patients were given either beclomethasone dipropionate (BDP) or placebo in a double-blind, randomized, crossover manner. Allergen challenges were performed after 1 wk of treatment. Nasal secretions were collected serially for 11 h after allergen challenge by a matrix method. Subjects maintained symptom scores at each time point of nasal secretion recovery. Cytokines were measured by specific enzyme-linked immunosorbent assays. The mean peak values for each cytokine and total symptom scores during the early (ER) and/or late-phase reactions (LPR) were significantly reduced during the BDP treatment period (p < 0.05). The levels of cytokine correlated (p < 0.05) with corresponding total symptom scores during ER (IL-1 beta and MIP-1 alpha) and LPR (all cytokines). Our findings document local elevations of IL-1 beta, GM-CSF, and chemokines in the nasal secretions after allergen challenges and their inhibition by steroids. We speculate that the inhibition of cytokine production and secretion in the nasal mucosa may contribute to the clinical efficacy of topical steroids.