Efficacy of a leukotriene receptor antagonist for pediatric cedar pollen allergy complicated by asthma

Leukotriene receptor antagonists (LTRAs) are identified as a monotherapy for asthma and allergic rhinitis; however, their use in children for treatment of these diseases has not been examined. Accordingly, the present study investigated the efficacy of pranlukast dry syrup for children with both pollinosis and asthma. The subjects were children receiving treatment for asthma who were also diagnosed with cedar pollen allergy. Patients were divided into a group that received continuous treatment with pranlukast (group A; n=20) and a group that commenced add‑on treatment for pollinosis following the onset of symptoms (group B; n=20). Patients in group B were randomly allocated to subgroup B1 (add-on treatment with pranlukast dry syrup) or subgroup B2 (add‑on treatment with a second-generation antihistamine). In both groups, nasal and ocular symptoms were evaluated every day and recorded in a diary. Exacerbation of nasal obstruction was demonstrated in group B; however, not in group A. There was a significant difference in symptoms observed between the two groups during the late peak pollen period (P<0.05). The incidence of nasal obstruction (defined as a nasal obstruction score ≥3 or use of a nasal steroid spray) was significantly lower in group A compared with group B (P<0.05). The maximum scores for sneezing and nasal obstruction during the late peak of the pollen season were lowest in group A, followed by subgroup B1 and subgroup B2. The present study demonstrated that long-term administration of LTRA for the management of asthma may improve nasal symptoms of pollinosis during the pollen season in children with pollinosis and asthma.