Pollen aeroallergen sensitization and efficacy of fexofenadine in children from the Southern Hemisphere*1

Rationale Allergen sensitization is an important risk factor for allergic disease, including allergic rhinitis. This study reports the sensitization status, and efficacy of fexofenadine (FEX), in a subset of children (aged 6–11 yrs) from the Southern Hemisphere with seasonal allergic rhinitis (SAR) enrolled into a large, placebo-controlled, randomized, parallel-group study. Methods For randomization, children required a positive skin prick test to at least one pollen allergen for the current season and concordance to that specific allergen in in vitro IgE testing. Specific IgEs were determined by the Fluoro Enzyme Immuno Assay; positive IgE was defined as IgE class ≥2 (>0.7 kUA/L). Analysis was performed on the modified intention-to-treat (mITT) population, treated with either FEX HCl 30 mg BID or placebo. Efficacy was evaluated as the overall mean change from baseline in 12-hour reflective total symptom score (TSS). Results A subset of 300 subjects (FEX, n=145; placebo, n=155), from 40 centers in Argentina, Chile, Uruguay and South Africa, was analyzed. Sensitization to pollen allergens assessed by plant category showed that grasses were the most common group of allergens (>93%); sensitization to weeds was 8.9% for FEX and 17.8% for placebo; sensitization to trees was 20.5% for FEX and 20.4% for placebo. FEX significantly improved the mean change from baseline in TSS compared with placebo ( p Conclusions In this subset of children from the Southern Hemisphere, grasses were the most common groups of sensitizing allergens. Furthermore, FEX significantly improved the symptoms of SAR in this population of children.