Few studies have investigated the use of specific immunotherapy (SIT) for childhood seasonal allergic asthma.

We sought to examine the efficacy and safety of SIT with Alutard SQ grass pollen (Phleum pratense Alutard SQ; ALK-Abelló, Hørsholm, Denmark) in children with seasonal allergic asthma.

A randomized, double-blind, placebo-controlled study assessing the efficacy of grass pollen SIT over 2 pollen seasons was performed. Children (3-16 years) with a history of seasonal allergic asthma sensitized to grass pollen (P pratense) and requiring at least 200 μg of inhaled beclomethasone equivalent per day were enrolled. Subjects with symptomatic asthma or rhinoconjunctivitis outside the grass pollen season were excluded. The primary outcome measure was a combined asthma symptom-medication score during the second pollen season. Secondary outcome measures included end-point titration skin prick testing and conjunctival and bronchial provocation testing to allergen, sputum eosinophilia, exhaled nitric oxide, and adverse events.

Thirty-nine subjects were enrolled. Thirty-five subjects provided data for analysis. The use of SIT was associated with a substantial reduction in asthma symptom-medication score compared with that after placebo (P = .04). There were also significant reductions in cutaneous (P = .002), conjunctival (P = .02), and bronchial (P = .01) reactivity to allergen after SIT compared with that after placebo. The 2 groups had similar levels of airway inflammation, despite a trend toward less inhaled steroid use in the active group. No serious adverse events were reported, and no subjects withdrew because of adverse events.

The study has shown that SIT is effective and well tolerated in children with seasonal allergic asthma to grass pollen.